mirror of
https://github.com/IllusionMan1212/flac-odin.git
synced 2026-10-24 02:12:29 +00:00
1165 lines
44 KiB
Odin
1165 lines
44 KiB
Odin
package flac
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import "core:bytes"
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import "core:crypto/legacy/md5"
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import "core:fmt"
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import "core:mem"
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import "core:math"
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import "core:slice"
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import "core:io"
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import "core:os"
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import "core:time"
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@(private)
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FLAC_MAGIC :: 'f' << 24 | 'L' << 16 | 'a' << 8 | 'C'
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@(private)
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crc8_lookup := [256]u8 {
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0x00, 0x07, 0x0E, 0x09, 0x1C, 0x1B, 0x12, 0x15,
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0x38, 0x3F, 0x36, 0x31, 0x24, 0x23, 0x2A, 0x2D,
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0x70, 0x77, 0x7E, 0x79, 0x6C, 0x6B, 0x62, 0x65,
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0x48, 0x4F, 0x46, 0x41, 0x54, 0x53, 0x5A, 0x5D,
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0xE0, 0xE7, 0xEE, 0xE9, 0xFC, 0xFB, 0xF2, 0xF5,
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0xD8, 0xDF, 0xD6, 0xD1, 0xC4, 0xC3, 0xCA, 0xCD,
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0x90, 0x97, 0x9E, 0x99, 0x8C, 0x8B, 0x82, 0x85,
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0xA8, 0xAF, 0xA6, 0xA1, 0xB4, 0xB3, 0xBA, 0xBD,
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0xC7, 0xC0, 0xC9, 0xCE, 0xDB, 0xDC, 0xD5, 0xD2,
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0xFF, 0xF8, 0xF1, 0xF6, 0xE3, 0xE4, 0xED, 0xEA,
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0xB7, 0xB0, 0xB9, 0xBE, 0xAB, 0xAC, 0xA5, 0xA2,
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0x8F, 0x88, 0x81, 0x86, 0x93, 0x94, 0x9D, 0x9A,
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0x27, 0x20, 0x29, 0x2E, 0x3B, 0x3C, 0x35, 0x32,
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0x1F, 0x18, 0x11, 0x16, 0x03, 0x04, 0x0D, 0x0A,
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0x57, 0x50, 0x59, 0x5E, 0x4B, 0x4C, 0x45, 0x42,
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0x6F, 0x68, 0x61, 0x66, 0x73, 0x74, 0x7D, 0x7A,
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0x89, 0x8E, 0x87, 0x80, 0x95, 0x92, 0x9B, 0x9C,
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0xB1, 0xB6, 0xBF, 0xB8, 0xAD, 0xAA, 0xA3, 0xA4,
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0xF9, 0xFE, 0xF7, 0xF0, 0xE5, 0xE2, 0xEB, 0xEC,
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0xC1, 0xC6, 0xCF, 0xC8, 0xDD, 0xDA, 0xD3, 0xD4,
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0x69, 0x6E, 0x67, 0x60, 0x75, 0x72, 0x7B, 0x7C,
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0x51, 0x56, 0x5F, 0x58, 0x4D, 0x4A, 0x43, 0x44,
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0x19, 0x1E, 0x17, 0x10, 0x05, 0x02, 0x0B, 0x0C,
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0x21, 0x26, 0x2F, 0x28, 0x3D, 0x3A, 0x33, 0x34,
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0x4E, 0x49, 0x40, 0x47, 0x52, 0x55, 0x5C, 0x5B,
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0x76, 0x71, 0x78, 0x7F, 0x6A, 0x6D, 0x64, 0x63,
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0x3E, 0x39, 0x30, 0x37, 0x22, 0x25, 0x2C, 0x2B,
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0x06, 0x01, 0x08, 0x0F, 0x1A, 0x1D, 0x14, 0x13,
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0xAE, 0xA9, 0xA0, 0xA7, 0xB2, 0xB5, 0xBC, 0xBB,
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0x96, 0x91, 0x98, 0x9F, 0x8A, 0x8D, 0x84, 0x83,
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0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB,
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0xE6, 0xE1, 0xE8, 0xEF, 0xFA, 0xFD, 0xF4, 0xF3,
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}
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@(private)
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crc16_lookup := [256]u16 {
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0x0000, 0x8005, 0x800F, 0x000A, 0x801B, 0x001E, 0x0014, 0x8011,
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0x8033, 0x0036, 0x003C, 0x8039, 0x0028, 0x802D, 0x8027, 0x0022,
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0x8063, 0x0066, 0x006C, 0x8069, 0x0078, 0x807D, 0x8077, 0x0072,
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0x0050, 0x8055, 0x805F, 0x005A, 0x804B, 0x004E, 0x0044, 0x8041,
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0x80C3, 0x00C6, 0x00CC, 0x80C9, 0x00D8, 0x80DD, 0x80D7, 0x00D2,
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0x00F0, 0x80F5, 0x80FF, 0x00FA, 0x80EB, 0x00EE, 0x00E4, 0x80E1,
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0x00A0, 0x80A5, 0x80AF, 0x00AA, 0x80BB, 0x00BE, 0x00B4, 0x80B1,
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0x8093, 0x0096, 0x009C, 0x8099, 0x0088, 0x808D, 0x8087, 0x0082,
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0x8183, 0x0186, 0x018C, 0x8189, 0x0198, 0x819D, 0x8197, 0x0192,
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0x01B0, 0x81B5, 0x81BF, 0x01BA, 0x81AB, 0x01AE, 0x01A4, 0x81A1,
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0x01E0, 0x81E5, 0x81EF, 0x01EA, 0x81FB, 0x01FE, 0x01F4, 0x81F1,
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0x81D3, 0x01D6, 0x01DC, 0x81D9, 0x01C8, 0x81CD, 0x81C7, 0x01C2,
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0x0140, 0x8145, 0x814F, 0x014A, 0x815B, 0x015E, 0x0154, 0x8151,
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0x8173, 0x0176, 0x017C, 0x8179, 0x0168, 0x816D, 0x8167, 0x0162,
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0x8123, 0x0126, 0x012C, 0x8129, 0x0138, 0x813D, 0x8137, 0x0132,
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0x0110, 0x8115, 0x811F, 0x011A, 0x810B, 0x010E, 0x0104, 0x8101,
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0x8303, 0x0306, 0x030C, 0x8309, 0x0318, 0x831D, 0x8317, 0x0312,
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0x0330, 0x8335, 0x833F, 0x033A, 0x832B, 0x032E, 0x0324, 0x8321,
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0x0360, 0x8365, 0x836F, 0x036A, 0x837B, 0x037E, 0x0374, 0x8371,
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0x8353, 0x0356, 0x035C, 0x8359, 0x0348, 0x834D, 0x8347, 0x0342,
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0x03C0, 0x83C5, 0x83CF, 0x03CA, 0x83DB, 0x03DE, 0x03D4, 0x83D1,
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0x83F3, 0x03F6, 0x03FC, 0x83F9, 0x03E8, 0x83ED, 0x83E7, 0x03E2,
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0x83A3, 0x03A6, 0x03AC, 0x83A9, 0x03B8, 0x83BD, 0x83B7, 0x03B2,
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0x0390, 0x8395, 0x839F, 0x039A, 0x838B, 0x038E, 0x0384, 0x8381,
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0x0280, 0x8285, 0x828F, 0x028A, 0x829B, 0x029E, 0x0294, 0x8291,
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0x82B3, 0x02B6, 0x02BC, 0x82B9, 0x02A8, 0x82AD, 0x82A7, 0x02A2,
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0x82E3, 0x02E6, 0x02EC, 0x82E9, 0x02F8, 0x82FD, 0x82F7, 0x02F2,
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0x02D0, 0x82D5, 0x82DF, 0x02DA, 0x82CB, 0x02CE, 0x02C4, 0x82C1,
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0x8243, 0x0246, 0x024C, 0x8249, 0x0258, 0x825D, 0x8257, 0x0252,
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0x0270, 0x8275, 0x827F, 0x027A, 0x826B, 0x026E, 0x0264, 0x8261,
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0x0220, 0x8225, 0x822F, 0x022A, 0x823B, 0x023E, 0x0234, 0x8231,
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0x8213, 0x0216, 0x021C, 0x8219, 0x0208, 0x820D, 0x8207, 0x0202,
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}
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md5_ctx: md5.Context
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decoded_samples: [dynamic]byte
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output_file: os.Handle
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Error :: union {
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io.Error,
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FlacError,
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}
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FlacError :: enum {
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Unable_To_Read_File,
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Invalid_Signature,
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Invalid_Sample_Rate,
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Missing_StreamInfo,
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Missing_Lead_Out_Track,
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Invalid_Coefficient_Precision,
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Metadata_Block_Length_Mismatch,
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CRC_Mismatch,
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MD5_Mismatch,
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Unimplemented_Utf8, // Remove
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Unsupported_BPS, // Remove
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Unencoded_BPS_For_Fixed_Subframe_Is_Unsupported, // Remove
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Invalid_Residual_Coding_Method,
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Invalid_Block_Size,
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Bits_Per_Second_Mismatch,
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}
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BlockType :: enum u16be {
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STREAMINFO,
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PADDING,
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APPLICATION,
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SEEKTABLE,
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VORBIS_COMMENT,
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CUESHEET,
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PICTURE,
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INVALID = 127,
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}
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PictureType :: enum u32be {
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OTHER,
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FILE_ICON_32x32_PNG,
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OTHER_FILE_ICON,
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COVER_FRONT,
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COVER_BACK,
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LEAFLET,
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MEDIA,
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LEAD_ARTIST,
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ARTIST,
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CONDUCTOR,
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BAND,
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COMPOSER,
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LYRICIST,
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RECORDING_LOCATION,
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DURING_RECORDING,
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DURING_PERFORMANCE,
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VIDEO_SCREEN_CAPTURE,
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BRIGHT_COLORED_FISH,
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ILLUSTRATION,
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ARTIST_LOGO,
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PUBLISHER_LOGO,
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}
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TrackType :: enum u8 {
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AUDIO,
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NONAUDIO,
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}
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BlockingStrategy :: enum {
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FIXED,
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VARIABLE,
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}
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SampleRate :: enum {
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USE_STREAMINFO,
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_88_2kHz,
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_176_4kHz,
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_192kHz,
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_8kHz,
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_16kHz,
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_22_05kHz,
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_24kHz,
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_32kHz,
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_44_1kHz,
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_48kHz,
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_96kHz,
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USE_8_BITS_IN_kHz_FROM_HEADER_END,
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USE_16_BITS_IN_Hz_FROM_HEADER_END,
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USE_16_BITS_IN_TENS_OF_Hz_FROM_HEADER_END,
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INVALID,
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}
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SampleSize :: enum {
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USE_STREAMINFO,
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_8BPS,
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_12BPS,
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// 011 is Reserved
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_16BPS = 4,
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_20BPS,
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_24BPS,
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_32BPS,
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}
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ChannelAssignment :: enum {
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MONO,
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_2CHANNEL,
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_3CHANNELS,
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_4CHANNELS,
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_5CHANNELS,
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_6CHANNELS,
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_7CHANNELS,
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_8CHANNELS,
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STEREO_LEFT_SIDE,
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STEREO_SIDE_RIGHT,
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STEREO_MID_SIDE,
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}
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ResidualCodingMethod :: enum {
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RICE,
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RICE2,
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}
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#assert(size_of(FlacHeader) == 0x2A)
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FlacHeader :: struct #packed {
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magic: u32be,
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streaminfo_header: u32be,
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streaminfo: StreamInfoBlock,
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}
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MetadataBlockHeader :: struct {
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type: BlockType,
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last_block: bool,
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length: u32,
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}
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#assert(size_of(Seekpoint) == 18)
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Seekpoint :: struct #packed {
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sample_num: u64be,
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offset: u64be,
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num_samples: u16be,
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}
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#assert(size_of(StreamInfoBlock) == 0x22)
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StreamInfoBlock :: struct #packed {
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min_block_size: u16be,
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using _: bit_field u64be {
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max_block_size: u16be | 16,
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min_frame_size: u32be | 24,
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max_frame_size: u32be | 24,
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},
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// This isn't a bit_field because odin's bitfields are LSB and it's hard (impossible?)
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// to read data into it if we're doing non-power-of-8 bits that don't form full bytes like 20bits, 3bits, 5 bits, 36bits
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// (although 3 and 5 is fine because they form a byte together, but 36 and 20 don't form full bytes)
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sr_chan_bps_ts: u64be,
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md5: [16]byte,
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}
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#assert(size_of(CueSheet) == 396)
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CueSheet :: struct #packed {
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media_catalog_num: [128]byte,
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num_lead_in_samples: u64be,
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using _: bit_field u8 {
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reserved: u8 | 7,
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compact_disc: bool | 1,
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},
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reserved: [258]byte,
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num_tracks: u8,
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}
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#assert(size_of(CueSheetTrack) == 36)
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CueSheetTrack :: struct #packed {
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track_offset: u64be,
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track_num: u8,
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ISRC: [12]byte,
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using _: bit_field u8 {
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reserved: u8 | 6,
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pre_emphasis: bool | 1,
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track_type: TrackType | 1,
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},
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reserved: [13]byte,
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num_track_index_points: u8,
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}
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#assert(size_of(CueSheetTrackIndex) == 12)
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CueSheetTrackIndex :: struct #packed {
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offset: u64be,
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index_point_number: u8,
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reserved: [3]byte,
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}
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decode_subframe :: proc(r: ^Reader, bps: u8, block_size: u16) -> Error {
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subframe_type_str := ""
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// TODO: temp allocator?? so we copy the slice of data into the _actual_ sample buffer
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// Maybe even a static arena with a size of 32MB by default (and configurable using #config) or something
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// that we then use to allocate from (better perf is the reason because allocating on the heap for every subframe
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// is probably noticibly slower)
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subframe_samples := make([dynamic]i32, 0, block_size)
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fmt.println("cur offset", r.i)
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fmt.println("cur offset bits", r.bits_read_in_byte)
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data := read_byte(r) or_return
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fmt.println("First subframe byte:", data)
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fmt.printfln("First subframe byte: 0b%b", data)
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subframe_type := (data & 0x7E) >> 1
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low_3_bits := subframe_type & 7
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has_wasted_bits := data & 1 == 1
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wasted_bits := 0
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fmt.println("has wasted bits:", has_wasted_bits)
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if has_wasted_bits {
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for (read_bit(r) or_return) != 1 {
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wasted_bits += 1
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}
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wasted_bits += 1
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fmt.println("wasted bits", wasted_bits)
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}
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if subframe_type == 0 { // CONSTANT
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fmt.println("SUBFRAME: CONSTANT")
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subframe_type_str = "CONSTANT"
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bits_to_read := int(bps) - wasted_bits
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// TODO: should we shift to the left by the number of wasted bits??
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sample := i32(read_bits(r, bits_to_read) or_return)
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if (sample >> (uint(bits_to_read) - 1)) & 1 == 1 {
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sample = -(((~sample) & i32(math.pow2_f32(bits_to_read) - 1)) + 1)
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}
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append(&subframe_samples, sample)
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} else if subframe_type == 1 { // VERBATIM
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fmt.println("SUBFRAME: VERBATIM")
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subframe_type_str = "VERBATIM"
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// We loop over the samples in the block here because each sample is BPS bits long.
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// Which I assume is always 16 but that's wrong because BPS can go as high as 32 bits
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// TODO: this will break if bits per sample is anything BUT 16
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if bps < 16 || bps > 17 {
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fmt.println("UNSUPPORTED BPS FOR VERBATIM SUBFRAME")
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return .Unsupported_BPS
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}
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for sample in 0..<block_size {
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bits_to_read := int(bps) - wasted_bits
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fmt.printfln("reading %d bits", bits_to_read)
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unencoded_subblock := u16((read_bits(r, bits_to_read) or_return)) << uint(wasted_bits)
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fmt.printfln("unencoded_subblock: %b", unencoded_subblock)
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fmt.println("unencoded_subblock:", unencoded_subblock)
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fmt.printfln("unencoded_subblock: 0x%X", unencoded_subblock)
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unencoded_subblock_arr := transmute([2]byte)unencoded_subblock
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fmt.printfln("arr: %X", unencoded_subblock_arr)
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fmt.printfln("arr as u16: %X", transmute(u16)unencoded_subblock_arr)
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// TODO: I think we'll want to append these samples to a local slice and return that (or a slice we pass in)
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append(&decoded_samples, ..unencoded_subblock_arr[:])
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}
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} else if (subframe_type >> 5) & 1 == 1 { // LPC
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fmt.println("SUBFRAME: LPC")
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subframe_type_str = "LPC"
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sample_i := 0
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predictor_order := (subframe_type & 0x1F) + 1
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fmt.println("predictor_order:", predictor_order)
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for sample in 0..<predictor_order {
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// NOTE: samples are signed so we do 2's complement
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bits_to_read := int(bps) - wasted_bits
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// TODO: should we shift to the left by the number of wasted bits??
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unencoded_warmup_sample := i32(read_bits(r, bits_to_read) or_return)
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if (unencoded_warmup_sample >> (uint(bits_to_read) - 1)) & 1 == 1 {
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unencoded_warmup_sample = -(((~unencoded_warmup_sample) & i32(math.pow2_f32(bits_to_read) - 1)) + 1)
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}
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//fmt.printfln("unencoded warmup sample: 0b%b", unencoded_warmup_sample)
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//fmt.println("unencoded warmup sample:", unencoded_warmup_sample)
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//fmt.printfln("unencoded warmup sample: 0x%X", unencoded_warmup_sample)
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append(&subframe_samples, unencoded_warmup_sample)
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}
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coeff_precision_minus_one := u8(read_bits(r, 4) or_return)
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if coeff_precision_minus_one == 0xF {
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return .Invalid_Coefficient_Precision
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}
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coeff_precision := coeff_precision_minus_one + 1
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coeff_bits_to_shift := i8(read_bits(r, 5) or_return)
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// NOTE: This is signed 2's complement so we check the MSB
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// NOTE: This is apparently supposed to never be a negative number according to the spec.
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if (coeff_bits_to_shift >> (5 - 1)) & 1 == 1 {
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fmt.println("BITS TO SHIFT IS NEGATIVE")
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coeff_bits_to_shift = -(((~coeff_bits_to_shift) & i8(math.pow2_f32(5) - 1)) + 1)
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}
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fmt.println("coeff precision", coeff_precision)
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fmt.println("coeff bits to shift", coeff_bits_to_shift)
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|
|
coefficients := make([]i32, predictor_order)
|
|
|
|
for i in 0..<predictor_order {
|
|
unencoded_coefficient := i32(read_bits(r, int(coeff_precision)) or_return)
|
|
// Ditto
|
|
if (unencoded_coefficient >> (coeff_precision - 1)) & 1 == 1 {
|
|
unencoded_coefficient = -(((~unencoded_coefficient) & i32(math.pow2_f32(coeff_precision) - 1)) + 1)
|
|
}
|
|
coefficients[i] = unencoded_coefficient
|
|
//fmt.println("unencoded_coefficient", unencoded_coefficient)
|
|
}
|
|
|
|
residual_coding_method := ResidualCodingMethod(read_bits(r, 2) or_return)
|
|
if residual_coding_method != .RICE && residual_coding_method != .RICE2 {
|
|
return .Invalid_Residual_Coding_Method
|
|
}
|
|
fmt.println(residual_coding_method)
|
|
|
|
partition_order := read_bits(r, 4) or_return
|
|
//fmt.println("parition order", partition_order)
|
|
partitions := int(math.pow2_f32(partition_order))
|
|
//fmt.println("partitions:", partitions)
|
|
//fmt.println("block_size:", block_size)
|
|
|
|
lpc_partitions_loop: for i in 0..<partitions {
|
|
rice_parameter := read_bits(r, residual_coding_method == .RICE ? 4 : 5) or_return
|
|
if (residual_coding_method == .RICE && rice_parameter == 15) || (residual_coding_method == .RICE2 && rice_parameter == 31) {
|
|
unencoded_bps := u8(read_bits(r, 5) or_return)
|
|
//fmt.println("unencoded_bps:", unencoded_bps)
|
|
|
|
num_samples := 0
|
|
if partition_order == 0 {
|
|
num_samples = int(block_size - u16(predictor_order))
|
|
} else if i != 0 {
|
|
num_samples = int(block_size / u16(math.pow2_f32(partition_order)))
|
|
} else {
|
|
num_samples = int((block_size / u16(math.pow2_f32(partition_order))) - u16(predictor_order))
|
|
}
|
|
|
|
if unencoded_bps == 0 {
|
|
for sample in 0..<num_samples {
|
|
append(&subframe_samples, i32(0))
|
|
}
|
|
continue lpc_partitions_loop
|
|
}
|
|
|
|
//fmt.printfln("ESCAPE reading %d samples for residual", num_samples)
|
|
|
|
for s in 0..<num_samples {
|
|
// NOTE: This is signed 2's complement so we check the MSB
|
|
residual_sample_value := i32(read_bits(r, int(unencoded_bps)) or_return)
|
|
if (residual_sample_value >> (unencoded_bps - 1)) & 1 == 1 {
|
|
residual_sample_value = -(((~residual_sample_value) & i32(math.pow2_f32(unencoded_bps) - 1)) + 1)
|
|
}
|
|
|
|
// Restore sample values using the predictor and the residual values
|
|
predictor_before_shift := 0
|
|
c := 0
|
|
#reverse for coefficient in coefficients {
|
|
//fmt.printfln("multiplying coefficient: %d with sample: %d", coefficient, subframe_samples[sample_i + c])
|
|
predictor_before_shift += int(coefficient) * int(subframe_samples[sample_i + c])
|
|
c += 1
|
|
}
|
|
|
|
if coeff_bits_to_shift < 0 {
|
|
fmt.println("TRYING TO SHIFT BY A NEGATIVE NUMBER. CHECK IF THE ARITHMETIC SHIFT IS CORRECT")
|
|
}
|
|
|
|
//fmt.println("predictor before shift", predictor_before_shift)
|
|
//fmt.println("shifting by", coeff_bits_to_shift)
|
|
|
|
// NOTE: Apply arithmetic right shift in case the bits to shift are negative
|
|
predictor := int(math.floor(f32(predictor_before_shift) / math.pow2_f32(coeff_bits_to_shift)))
|
|
//predictor := predictor_before_shift >> u8(coeff_bits_to_shift)
|
|
//fmt.println("predictor:", predictor)
|
|
|
|
sample := i32(predictor) + residual_sample_value
|
|
append(&subframe_samples, sample)
|
|
//fmt.println("residual sample value:", residual_sample_value)
|
|
//fmt.println("sample value:", sample)
|
|
sample_i += 1
|
|
}
|
|
} else {
|
|
//fmt.println("rice parameter:", rice_parameter)
|
|
|
|
num_samples := 0
|
|
if partition_order == 0 {
|
|
num_samples = int(block_size - u16(predictor_order))
|
|
} else if i != 0 {
|
|
num_samples = int(block_size / u16(math.pow2_f32(partition_order)))
|
|
} else {
|
|
num_samples = int((block_size / u16(math.pow2_f32(partition_order))) - u16(predictor_order))
|
|
}
|
|
//fmt.printfln("reading %d samples for residual", num_samples)
|
|
|
|
//
|
|
// Undo the RICE coding
|
|
//
|
|
previous_sample_value := 0
|
|
for j in 0..<num_samples {
|
|
quotient := 0
|
|
// Read bits until we encounter a 1 (also called unary encoding). That's our quotient.
|
|
for (read_bit(r) or_return) != 1 {
|
|
quotient += 1
|
|
}
|
|
remainder := int(read_bits(r, int(rice_parameter)) or_return)
|
|
|
|
//fmt.println("quotient:", quotient)
|
|
//fmt.println("remainder:", remainder)
|
|
|
|
zigzag_encoded_value := quotient * int(math.pow2_f32(rice_parameter)) + remainder
|
|
|
|
// Unzigzag the residual sample values
|
|
residual_sample_value := zigzag_encoded_value % 2 == 0 ? zigzag_encoded_value / 2 : (zigzag_encoded_value + 1) / -2
|
|
|
|
// Restore sample values using the predictor and the residual values
|
|
predictor_before_shift := 0
|
|
c := 0
|
|
#reverse for coefficient in coefficients {
|
|
//fmt.printfln("multiplying coefficient: %d with sample: %d", coefficient, subframe_samples[sample_i + c])
|
|
predictor_before_shift += int(coefficient) * int(subframe_samples[sample_i + c])
|
|
c += 1
|
|
}
|
|
|
|
if coeff_bits_to_shift < 0 {
|
|
fmt.println("TRYING TO SHIFT BY A NEGATIVE NUMBER. CHECK IF THE ARITHMETIC SHIFT IS CORRECT")
|
|
}
|
|
|
|
//fmt.println("predictor before shift", predictor_before_shift)
|
|
//fmt.println("shifting by", coeff_bits_to_shift)
|
|
|
|
// NOTE: Apply arithmetic right shift in case the bits to shift are negative
|
|
predictor := int(math.floor(f32(predictor_before_shift) / math.pow2_f32(coeff_bits_to_shift)))
|
|
//predictor := predictor_before_shift >> u8(coeff_bits_to_shift)
|
|
//fmt.println("predictor:", predictor)
|
|
|
|
sample := predictor + residual_sample_value
|
|
append(&subframe_samples, i32(sample))
|
|
|
|
sample_i += 1
|
|
//fmt.println("residual sample value:", residual_sample_value)
|
|
//fmt.println("sample value:", sample)
|
|
}
|
|
}
|
|
}
|
|
|
|
//fmt.printfln("%d", subframe_samples)
|
|
fmt.printfln("len: %d", len(subframe_samples))
|
|
} else if (subframe_type >> 3) & 1 == 1 && low_3_bits <= 4 { // FIXED
|
|
fmt.println("SUBFRAME: FIXED")
|
|
subframe_type_str = "FIXED"
|
|
predictor_order := low_3_bits
|
|
fmt.println("predictor_order:", predictor_order)
|
|
|
|
// "As a predictor makes use of samples preceding the sample that is
|
|
// predicted, it can only be used when enough samples are known. As
|
|
// each subframe in FLAC is coded completely independently, the first
|
|
// few samples in each subframe cannot be predicted. Therefore, a
|
|
// number of so-called warm-up samples equal to the predictor order is
|
|
// stored"
|
|
bits_to_read := bps - u8(wasted_bits)
|
|
unencoded_samples_n := bits_to_read * predictor_order
|
|
//fmt.println("unencoded warmup samples n:", unencoded_samples_n)
|
|
|
|
// NOTE: samples can be negative
|
|
// TODO: should we shift to the left by the number of wasted bits??
|
|
unencoded_warmup_sample := i32(read_bits(r, int(unencoded_samples_n)) or_return)
|
|
if (unencoded_warmup_sample >> (uint(bits_to_read) - 1)) & 1 == 1 {
|
|
unencoded_warmup_sample = -(((~unencoded_warmup_sample) & i32(math.pow2_f32(bits_to_read) - 1)) + 1)
|
|
}
|
|
fmt.println("unencoded warmup sample:", unencoded_warmup_sample)
|
|
fmt.printfln("unencoded warmup sample: 0x%X", unencoded_warmup_sample)
|
|
|
|
residual_coding_method := ResidualCodingMethod(read_bits(r, 2) or_return)
|
|
if residual_coding_method != .RICE && residual_coding_method != .RICE2 {
|
|
return .Invalid_Residual_Coding_Method
|
|
}
|
|
fmt.println(residual_coding_method)
|
|
|
|
partition_order := read_bits(r, 4) or_return
|
|
fmt.println("parition order", partition_order)
|
|
partitions := int(math.pow2_f32(partition_order))
|
|
fmt.println("partitions:", partitions)
|
|
//fmt.println("block_size:", block_size)
|
|
|
|
fixed_partitions_loop: for i in 0..<partitions {
|
|
rice_parameter := read_bits(r, residual_coding_method == .RICE ? 4 : 5) or_return
|
|
if (residual_coding_method == .RICE && rice_parameter == 15) || (residual_coding_method == .RICE2 && rice_parameter == 31) {
|
|
unencoded_bps := u8(read_bits(r, 5) or_return)
|
|
fmt.println("unencoded_bps:", unencoded_bps)
|
|
|
|
num_samples := 0
|
|
if partition_order == 0 {
|
|
num_samples = int(block_size - u16(predictor_order))
|
|
} else if i != 0 {
|
|
num_samples = int(block_size / u16(math.pow2_f32(partition_order)))
|
|
} else {
|
|
num_samples = int((block_size / u16(math.pow2_f32(partition_order))) - u16(predictor_order))
|
|
}
|
|
|
|
if unencoded_bps == 0 {
|
|
for sample in 0..<num_samples {
|
|
append(&subframe_samples, i32(0))
|
|
}
|
|
continue fixed_partitions_loop
|
|
}
|
|
|
|
fmt.printfln("reading %d samples for residual", num_samples)
|
|
|
|
for sample in 0..<num_samples {
|
|
// NOTE: This is signed 2's complement so we check the MSB
|
|
residual_sample_value := i8(read_bits(r, int(unencoded_bps)) or_return)
|
|
if (residual_sample_value >> (unencoded_bps - 1)) & 1 == 1 {
|
|
residual_sample_value = -(((~residual_sample_value) & i8(math.pow2_f32(unencoded_bps) - 1)) + 1)
|
|
}
|
|
|
|
fmt.println("residual sample value:", residual_sample_value)
|
|
}
|
|
|
|
return .Unencoded_BPS_For_Fixed_Subframe_Is_Unsupported
|
|
|
|
// TODO: calculate the actual sample value by using the residual AND the previous sample value
|
|
// TODO: add the samples to something ??
|
|
} else {
|
|
fmt.println("rice parameter:", rice_parameter)
|
|
|
|
samples := 0
|
|
if partition_order == 0 {
|
|
samples = int(block_size - u16(predictor_order))
|
|
} else if i != 0 {
|
|
samples = int(block_size / u16(math.pow2_f32(partition_order)))
|
|
} else {
|
|
samples = int((block_size / u16(math.pow2_f32(partition_order))) - u16(predictor_order))
|
|
}
|
|
fmt.printfln("reading %d samples for residual", samples)
|
|
|
|
//
|
|
// Undo the RICE coding
|
|
//
|
|
previous_sample_value := 0
|
|
for j in 0..<samples {
|
|
quotient := 0
|
|
// Read bits until we encounter a 1 (also called unary encoding). That's our quotient.
|
|
for (read_bit(r) or_return) != 1 {
|
|
quotient += 1
|
|
}
|
|
remainder := int(read_bits(r, int(rice_parameter)) or_return)
|
|
|
|
fmt.println("quotient:", quotient)
|
|
fmt.println("remainder:", remainder)
|
|
|
|
zigzag_encoded_value := quotient * int(math.pow2_f32(rice_parameter)) + remainder
|
|
|
|
// Unzigzag the residual sample values
|
|
residual_sample_value := zigzag_encoded_value % 2 == 0 ? zigzag_encoded_value / 2 : (zigzag_encoded_value + 1) / -2
|
|
|
|
fmt.println("residual sample value:", residual_sample_value)
|
|
|
|
// Restore sample values using the predictor and the residual values
|
|
sample_value := j == 0 ? residual_sample_value + int(unencoded_warmup_sample) : residual_sample_value + previous_sample_value
|
|
previous_sample_value = sample_value
|
|
|
|
fmt.println("sample_value:", sample_value)
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// TODO: Maybe this is slow if we have a lot of samples??
|
|
// The cases are ranges because streaminfo can define unusual bits per sample
|
|
for sample in subframe_samples {
|
|
switch bps {
|
|
case 1..=8:
|
|
data := []u8{u8(sample)}
|
|
os.write(output_file, data)
|
|
md5.update(&md5_ctx, data)
|
|
case 9..=16:
|
|
first_byte := i8(sample & 0xFF)
|
|
second_byte := i8((sample >> 8) & 0xFF)
|
|
data := slice.reinterpret([]u8, []i8{first_byte, second_byte})
|
|
os.write(output_file, data)
|
|
md5.update(&md5_ctx, data)
|
|
case 17..=24:
|
|
first_byte := i8(sample & 0xFF)
|
|
second_byte := i8((sample >> 8) & 0xFF)
|
|
third_byte := i8((sample >> 16) & 0xFF)
|
|
data := slice.reinterpret([]u8, []i8{first_byte, second_byte, third_byte})
|
|
os.write(output_file, data)
|
|
md5.update(&md5_ctx, data)
|
|
case 25..=32:
|
|
first_byte := i8(sample & 0xFF)
|
|
second_byte := i8((sample >> 8) & 0xFF)
|
|
third_byte := i8((sample >> 16) & 0xFF)
|
|
fourth_byte := i8((sample >> 24) & 0xFF)
|
|
data := slice.reinterpret([]u8, []i8{first_byte, second_byte, third_byte, fourth_byte})
|
|
os.write(output_file, data)
|
|
md5.update(&md5_ctx, data)
|
|
}
|
|
}
|
|
|
|
fmt.println("cur offset", r.i)
|
|
fmt.println("cur offset bits", r.bits_read_in_byte)
|
|
|
|
fmt.println("FINISHED SUBFRAME:", subframe_type_str)
|
|
|
|
return nil
|
|
}
|
|
|
|
// TODO: remove
|
|
frame_num := 0
|
|
|
|
decode_frame :: proc(r: ^Reader, streaminfo_bps: u8, streaminfo_sample_rate: u32, channels: u8) -> (err: Error) {
|
|
//
|
|
// Frame Header
|
|
//
|
|
frame_beginning := r.i
|
|
|
|
fmt.println("FRAME START AT OFFSET:", r.i)
|
|
|
|
data := read_data(r, u16be) or_return
|
|
|
|
sync_code := data >> 2
|
|
blocking_strategy := BlockingStrategy(data & 1)
|
|
fmt.println("blocking strategy:", blocking_strategy)
|
|
|
|
data = read_data(r, u16be) or_return
|
|
block_size := data >> 12
|
|
sample_rate := SampleRate((data >> 8) & 0xF)
|
|
channel_assignment := ChannelAssignment((data >> 4) & 0xF)
|
|
sample_size := SampleSize((data >> 1) & 7)
|
|
|
|
coded_num := decode_extended_utf8(r) or_return
|
|
if blocking_strategy == .VARIABLE {
|
|
// Sample number of first sample
|
|
// MUST NOT be larger than 36 bits unencoded or 7 bytes encoded.
|
|
// MUST be equal to the number of samples preceding the current frame. Otherwise seeking is not possible.
|
|
// TODO: also write a check for the number of samples so we'll probably keep track of how many samples we decoded
|
|
// maybe the number of decoded samples can be inferred by the number of frames ?? or just use the length of
|
|
// the decoded_samples slice.
|
|
if coded_num > 0x1000000000 {
|
|
// TODO: Sample number can't be bigger than 36 bits
|
|
}
|
|
} else {
|
|
// Frame number
|
|
// MUST NOT be larger than 31 bits unencoded or 6 bytes encoded.
|
|
// MUST be equal to the number of frames preceding the current frame. Otherwise seeking is not possible.
|
|
// TODO: also write a check for the number of frames so we'll probably keep track of how many frames we decoded.
|
|
if coded_num > 0x80000000 {
|
|
// TODO: Frame number cannot be bigger than 31 bits
|
|
}
|
|
}
|
|
|
|
actual_block_size: u16be
|
|
switch block_size {
|
|
case 1:
|
|
actual_block_size = 192
|
|
case 2..=5:
|
|
actual_block_size = 576 * auto_cast (math.pow2_f32(block_size - 2))
|
|
case 6:
|
|
actual_block_size = auto_cast (read_byte(r) or_return) + 1
|
|
case 7:
|
|
actual_block_size = (read_data(r, u16be) or_return) + 1
|
|
case 8..=15:
|
|
actual_block_size = 256 * auto_cast (math.pow2_f32(block_size - 8))
|
|
case:
|
|
return .Invalid_Block_Size
|
|
}
|
|
|
|
//if actual_block_size < 15 && !last_frame {
|
|
// TODO: block sizes less than 16 are only valid for the last frame and MUST NOT be used for any other frame.
|
|
//}
|
|
|
|
actual_sample_rate_in_Hz: u32
|
|
switch sample_rate {
|
|
case .USE_STREAMINFO:
|
|
// TODO: ditto for global streaminfo
|
|
actual_sample_rate_in_Hz = streaminfo_sample_rate
|
|
case ._88_2kHz:
|
|
actual_sample_rate_in_Hz = 88200
|
|
case ._176_4kHz:
|
|
actual_sample_rate_in_Hz = 176400
|
|
case ._192kHz:
|
|
actual_sample_rate_in_Hz = 192000
|
|
case ._8kHz:
|
|
actual_sample_rate_in_Hz = 8000
|
|
case ._16kHz:
|
|
actual_sample_rate_in_Hz = 16000
|
|
case ._22_05kHz:
|
|
actual_sample_rate_in_Hz = 22005
|
|
case ._24kHz:
|
|
actual_sample_rate_in_Hz = 24000
|
|
case ._32kHz:
|
|
actual_sample_rate_in_Hz = 32000
|
|
case ._44_1kHz:
|
|
actual_sample_rate_in_Hz = 44100
|
|
case ._48kHz:
|
|
actual_sample_rate_in_Hz = 48000
|
|
case ._96kHz:
|
|
actual_sample_rate_in_Hz = 96000
|
|
case .USE_8_BITS_IN_kHz_FROM_HEADER_END:
|
|
actual_sample_rate_in_Hz = auto_cast (read_byte(r) or_return) * 1000
|
|
case .USE_16_BITS_IN_Hz_FROM_HEADER_END:
|
|
actual_sample_rate_in_Hz = auto_cast (read_data(r, u16be) or_return)
|
|
case .USE_16_BITS_IN_TENS_OF_Hz_FROM_HEADER_END:
|
|
actual_sample_rate_in_Hz = auto_cast (read_data(r, u16be) or_return) * 10
|
|
case .INVALID: fallthrough
|
|
case:
|
|
return .Invalid_Sample_Rate
|
|
}
|
|
|
|
// TODO: sample rate MUST NOT be 0 if the subframe contains audio.
|
|
// a sample rate of 0 MAY be used when non-audio is represented.
|
|
|
|
frame_header_end := r.i
|
|
|
|
frame_header_crc := read_byte(r) or_return
|
|
calculated_header_crc := calculate_crc8(r.s[frame_beginning:frame_header_end])
|
|
|
|
fmt.printfln("block size bits: 0b%b", block_size)
|
|
fmt.printfln("actual block size: %d sample(s)", actual_block_size)
|
|
fmt.println("sample rate bits:", sample_rate)
|
|
fmt.printfln("actual sample rate: %dHz", actual_sample_rate_in_Hz)
|
|
fmt.println("channel assignment:", channel_assignment)
|
|
|
|
if frame_header_crc != calculated_header_crc {
|
|
fmt.printfln("Expected frame header CRC: 0x%X, got: 0x%X", frame_header_crc, calculated_header_crc)
|
|
return .CRC_Mismatch
|
|
}
|
|
|
|
//
|
|
// Subframes
|
|
//
|
|
bps: u8
|
|
switch sample_size {
|
|
case .USE_STREAMINFO:
|
|
// TODO: maybe we'll store the streaminfo data in a global flac struct and then retrieve from there
|
|
// instead of passing a parameter
|
|
bps = streaminfo_bps
|
|
case ._8BPS:
|
|
bps = 8
|
|
case ._12BPS:
|
|
bps = 12
|
|
case ._16BPS:
|
|
bps = 16
|
|
case ._20BPS:
|
|
bps = 20
|
|
case ._24BPS:
|
|
bps = 24
|
|
case ._32BPS:
|
|
bps = 32
|
|
}
|
|
|
|
fmt.println("channels:", channels)
|
|
fmt.println("bps:", bps)
|
|
fmt.println("sample size:", sample_size)
|
|
fmt.println("cur offset:", r.i)
|
|
fmt.println("cur offset bits:", r.bits_read_in_byte)
|
|
|
|
if bps != streaminfo_bps {
|
|
return .Bits_Per_Second_Mismatch
|
|
}
|
|
|
|
for i in 0..<channels {
|
|
frame_bps := bps
|
|
// For side channels we increase the bps by 1
|
|
// Left, mid and right channels don't need an extra bit.
|
|
// ref: https://github.com/ietf-wg-cellar/flac-specification/blob/master/rfc_backmatter.md#first-audio-frame
|
|
if (channel_assignment == .STEREO_SIDE_RIGHT && i == 0) ||
|
|
((channel_assignment == .STEREO_LEFT_SIDE || channel_assignment == .STEREO_MID_SIDE) && i == 1) {
|
|
frame_bps += 1
|
|
}
|
|
|
|
decode_subframe(r, frame_bps, auto_cast actual_block_size) or_return
|
|
}
|
|
|
|
align_to_byte(r)
|
|
|
|
// TODO: for stereo with side channels we must decorrelate the samples depending on the channel assignment
|
|
// otherwise we'll be saving incorrect samples.
|
|
|
|
//
|
|
// Frame Footer
|
|
//
|
|
frame_end := r.i
|
|
frame_crc := read_data(r, u16be) or_return
|
|
calculated_frame_crc := calculate_crc16(r.s[frame_beginning:frame_end])
|
|
|
|
fmt.println("FINISHED FRAME", frame_num)
|
|
|
|
if auto_cast frame_crc != calculated_frame_crc {
|
|
fmt.eprintfln("Expected frame CRC 0x%X, got 0x%X", frame_crc, calculated_frame_crc)
|
|
return .CRC_Mismatch
|
|
}
|
|
|
|
frame_num += 1
|
|
|
|
|
|
return nil
|
|
}
|
|
|
|
//@(optimization_mode="speed")
|
|
//calculate_crc8_simple :: proc(data: []byte) -> (crc: u8) #no_bounds_check {
|
|
// for i in 0..<len(data) {
|
|
// crc ~= data[i]
|
|
//
|
|
// for j in 0..<8 {
|
|
// if crc & 0x80 == 0x80 { // MSB is 1
|
|
// crc = (crc << 1) ~ POLYNOMIAL8
|
|
// } else {
|
|
// crc <<= 1
|
|
// }
|
|
// }
|
|
// }
|
|
//
|
|
// return
|
|
//}
|
|
|
|
@(optimization_mode="speed")
|
|
calculate_crc8 :: proc(data: []byte) -> u8 #no_bounds_check {
|
|
crc: u8 = 0
|
|
|
|
for i in 0..<len(data) {
|
|
crc = crc8_lookup[crc ~ data[i]]
|
|
}
|
|
|
|
return crc
|
|
}
|
|
|
|
@(optimization_mode="speed")
|
|
calculate_crc16 :: proc(data: []byte) -> u16 #no_bounds_check {
|
|
crc: u16 = 0
|
|
|
|
for i in 0..<len(data) {
|
|
byte := u16(data[i])
|
|
pos := (crc >> 8) ~ byte
|
|
crc = (crc << 8) ~ crc16_lookup[pos]
|
|
}
|
|
|
|
return crc
|
|
}
|
|
|
|
decode_extended_utf8 :: proc(r: ^Reader) -> (decoded_num: u64, err: Error) {
|
|
MASKX :: 0b0011_1111
|
|
MASK2 :: 0b0001_1111
|
|
MASK3 :: 0b0000_1111
|
|
MASK4 :: 0b0000_0111
|
|
MASK5 :: 0b0000_0011
|
|
MASK6 :: 0b0000_0001
|
|
|
|
decoded_num = u64(0)
|
|
|
|
first_byte := read_byte(r) or_return
|
|
utf8_sequence_len := 0
|
|
|
|
for i: uint = 7; i > 0; i -= 1 {
|
|
bit := (first_byte >> i) & 1
|
|
if bit == 1 {
|
|
utf8_sequence_len += 1
|
|
} else {
|
|
break
|
|
}
|
|
}
|
|
|
|
if utf8_sequence_len > 0 {
|
|
octets := make([dynamic]byte, 0, 8)
|
|
for i := utf8_sequence_len - 1; i > 0; i -= 1 {
|
|
append(&octets, read_byte(r) or_return)
|
|
}
|
|
|
|
switch utf8_sequence_len {
|
|
case 2:
|
|
decoded_num = (u64(first_byte) & MASK2) << 6 | (u64(octets[0]) & MASKX)
|
|
case 3:
|
|
decoded_num = (u64(first_byte) & MASK3) << 12 | (u64(octets[0]) & MASKX) << 6 | (u64(octets[1]) & MASKX)
|
|
case 4:
|
|
decoded_num = (u64(first_byte) & MASK4) << 18 | (u64(octets[0]) & MASKX) << 12 | (u64(octets[1]) & MASKX) << 6 | (u64(octets[2]) & MASKX)
|
|
case 5:
|
|
decoded_num = (u64(first_byte) & MASK5) << 24 | (u64(octets[0]) & MASKX) << 18 | (u64(octets[1]) & MASKX) << 12 | (u64(octets[2]) & MASKX) << 6 | (u64(octets[3]) & MASKX)
|
|
case 6:
|
|
decoded_num = (u64(first_byte) & MASK6) << 30 | (u64(octets[0]) & MASKX) << 24 | (u64(octets[1]) & MASKX) << 18 | (u64(octets[2]) & MASKX) << 12 | (u64(octets[3]) & MASKX) << 6 | (u64(octets[4]) & MASKX)
|
|
case 7:
|
|
decoded_num = (u64(octets[0]) & MASKX) << 30 | (u64(octets[1]) & MASKX) << 24 | (u64(octets[2]) & MASKX) << 18 | (u64(octets[3]) & MASKX) << 12 | (u64(octets[4]) & MASKX) << 6 | (u64(octets[5]) & MASKX)
|
|
}
|
|
} else {
|
|
decoded_num = u64(first_byte & 0x7F)
|
|
}
|
|
|
|
fmt.println("decoded num:", decoded_num)
|
|
|
|
return decoded_num, nil
|
|
}
|
|
|
|
load_from_bytes :: proc(data: []byte, allocator := context.allocator) -> (err: Error) {
|
|
r: Reader
|
|
bytes.reader_init(&r, data)
|
|
|
|
md5.init(&md5_ctx)
|
|
defer md5.reset(&md5_ctx)
|
|
|
|
header := read_data(&r, FlacHeader) or_return
|
|
if header.magic != FLAC_MAGIC {
|
|
return .Invalid_Signature
|
|
}
|
|
|
|
fmt.println(header)
|
|
|
|
/*bit_field u64be {
|
|
sample_rate: u32be | 20,
|
|
num_channel_minus_one: u8 | 3,
|
|
bits_per_sample_minus_one: u8 | 5,
|
|
total_samples: u64be | 36,
|
|
}*/
|
|
sample_rate := header.streaminfo.sr_chan_bps_ts >> 44
|
|
num_channel_minus_one := (header.streaminfo.sr_chan_bps_ts >> 41) & 7
|
|
bits_per_sample_minus_one := (header.streaminfo.sr_chan_bps_ts >> 36) & 0x1F
|
|
total_samples := header.streaminfo.sr_chan_bps_ts & 0xFFFFFFFFF
|
|
|
|
fmt.println("sample rate:", sample_rate)
|
|
fmt.println("channels:", num_channel_minus_one + 1)
|
|
fmt.println("bits per sample:", bits_per_sample_minus_one + 1)
|
|
fmt.println("total samples:", total_samples)
|
|
|
|
/*bit_field u32be {
|
|
last_block: bool | 1,
|
|
type: BlockType | 7,
|
|
length: u32be | 24,
|
|
}*/
|
|
streaminfo_header := MetadataBlockHeader{
|
|
last_block = bool(header.streaminfo_header >> 31),
|
|
type = BlockType((header.streaminfo_header >> 24) & 0x7F),
|
|
length = u32(header.streaminfo_header & 0xFFFFFF),
|
|
}
|
|
|
|
if streaminfo_header.type != .STREAMINFO {
|
|
return .Missing_StreamInfo
|
|
}
|
|
|
|
last_block := streaminfo_header.last_block
|
|
for !last_block {
|
|
md_block_hdr := read_data(&r, u32be) or_return
|
|
metadata_block_header := MetadataBlockHeader{
|
|
last_block = bool(md_block_hdr >> 31),
|
|
type = BlockType((md_block_hdr >> 24) & 0x7F),
|
|
length = u32(md_block_hdr & 0xFFFFFF),
|
|
}
|
|
fmt.println("Metadata block", metadata_block_header)
|
|
|
|
last_block = cast(bool)(metadata_block_header.last_block)
|
|
|
|
switch metadata_block_header.type {
|
|
case .STREAMINFO:
|
|
// Do nothing, we already parse the mandatory streaminfo metadata
|
|
case .PADDING:
|
|
fmt.printfln("Skipping %d bytes of padding data", metadata_block_header.length)
|
|
bytes.reader_seek(&r, auto_cast metadata_block_header.length, .Current)
|
|
case .APPLICATION:
|
|
//app_id := read_slice(&r, 4) or_return
|
|
//fmt.println("Found application with ID:", string(app_id))
|
|
fmt.printfln("Skipping %d bytes of application metadata block", metadata_block_header.length)
|
|
bytes.reader_seek(&r, auto_cast metadata_block_header.length, .Current)
|
|
// TODO: handle the application data
|
|
case .SEEKTABLE:
|
|
// TODO: check for size mismatch?
|
|
seekpoints := metadata_block_header.length / 18
|
|
fmt.printfln("we have %d seekpoints", seekpoints)
|
|
for i in 0..<seekpoints {
|
|
seekpoint := read_data(&r, Seekpoint) or_return
|
|
fmt.println(seekpoint)
|
|
}
|
|
case .VORBIS_COMMENT:
|
|
// TODO: save this info to a struct
|
|
vendor_name_len := read_data(&r, u32le) or_return
|
|
vendor_name := string(read_slice(&r, auto_cast vendor_name_len) or_return)
|
|
user_comment_list_len := read_data(&r, u32le) or_return
|
|
|
|
actual_size := 4 + vendor_name_len + 4
|
|
|
|
for i in 0..<user_comment_list_len {
|
|
comment_len := read_data(&r, u32le) or_return
|
|
comment := string(read_slice(&r, auto_cast comment_len) or_return)
|
|
fmt.println(comment)
|
|
actual_size += 4 + comment_len
|
|
}
|
|
if metadata_block_header.length != u32(actual_size) {
|
|
// TODO: should this be a warning instead of an error that halts the decoding?
|
|
// I think so, the comment isn't crucial to the decoding process.
|
|
fmt.println("Metadata header length mismatch!")
|
|
fmt.printfln("Expected size: %d, Got %d", metadata_block_header.length, actual_size)
|
|
return .Metadata_Block_Length_Mismatch
|
|
}
|
|
// TODO: framing bit??
|
|
fmt.println(vendor_name)
|
|
case .CUESHEET:
|
|
// TODO: save this to a struct
|
|
// + there's some CD-DA stuff that we need to consider I think
|
|
cuesheet := read_data(&r, CueSheet) or_return
|
|
if cuesheet.num_tracks < 1 {
|
|
// TODO: should this be a warning instead of an error that halts the decoding?
|
|
return .Missing_Lead_Out_Track
|
|
}
|
|
fmt.println(cuesheet)
|
|
for i in 0..<cuesheet.num_tracks {
|
|
track := read_data(&r, CueSheetTrack) or_return
|
|
for i in 0..<track.num_track_index_points {
|
|
track_index := read_data(&r, CueSheetTrackIndex) or_return
|
|
fmt.println(track_index)
|
|
}
|
|
fmt.println(track)
|
|
}
|
|
case .PICTURE:
|
|
// TODO: save the pic data into a struct
|
|
// TODO: maybe put all of these into a struct so we do one big read?
|
|
pic_type := read_data(&r, PictureType) or_return
|
|
mime_len := read_data(&r, u32be) or_return
|
|
mimetype := string(read_slice(&r, auto_cast mime_len) or_return)
|
|
desc_len := read_data(&r, u32be) or_return
|
|
desc := string(read_slice(&r, auto_cast desc_len) or_return)
|
|
width := read_data(&r, u32be) or_return
|
|
height := read_data(&r, u32be) or_return
|
|
depth := read_data(&r, u32be) or_return
|
|
num_colors := read_data(&r, u32be) or_return
|
|
data_len := read_data(&r, u32be) or_return
|
|
data := read_slice(&r, auto_cast data_len) or_return
|
|
fmt.println(pic_type)
|
|
fmt.println(mimetype)
|
|
fmt.println(desc)
|
|
fmt.println(width)
|
|
fmt.println(height)
|
|
fmt.println(depth)
|
|
fmt.println(num_colors)
|
|
fmt.println(data_len)
|
|
//fmt.println(data)
|
|
case .INVALID:
|
|
fmt.eprintln("Invalid block type")
|
|
bytes.reader_seek(&r, auto_cast metadata_block_header.length, .Current)
|
|
case:
|
|
fmt.printfln("Skipping %d bytes of Unknown metadata block", metadata_block_header.length)
|
|
bytes.reader_seek(&r, auto_cast metadata_block_header.length, .Current)
|
|
}
|
|
}
|
|
|
|
// Yucky
|
|
err = decode_frame(&r, u8(bits_per_sample_minus_one + 1), u32(sample_rate), u8(num_channel_minus_one + 1))
|
|
for err == nil {
|
|
err = decode_frame(&r, u8(bits_per_sample_minus_one + 1), u32(sample_rate), u8(num_channel_minus_one + 1))
|
|
}
|
|
|
|
if err != .EOF {
|
|
return err
|
|
}
|
|
|
|
//
|
|
// Validate the decoded audio data's md5
|
|
//
|
|
calculated_md5 := make([]byte, 16)
|
|
md5.final(&md5_ctx, calculated_md5)
|
|
|
|
if mem.compare(calculated_md5, header.streaminfo.md5[:]) != 0 {
|
|
fmt.printfln("expected: %X", header.streaminfo.md5)
|
|
fmt.printfln("got: %X", calculated_md5)
|
|
return .MD5_Mismatch
|
|
}
|
|
|
|
return nil
|
|
}
|
|
|
|
load_from_file :: proc(filename: string, allocator := context.allocator) -> (err: Error) {
|
|
context.allocator = allocator
|
|
|
|
output_file, _ = os.open("output.raw", os.O_WRONLY | os.O_CREATE | os.O_TRUNC, 0o664)
|
|
defer os.close(output_file)
|
|
|
|
data, ok := os.read_entire_file(filename)
|
|
defer delete(data)
|
|
|
|
if ok {
|
|
return load_from_bytes(data)
|
|
} else {
|
|
return .Unable_To_Read_File
|
|
}
|
|
}
|