| 1 | /* |
| 2 | * FLAC common code |
| 3 | * Copyright (c) 2009 Justin Ruggles |
| 4 | * |
| 5 | * This file is part of FFmpeg. |
| 6 | * |
| 7 | * FFmpeg is free software; you can redistribute it and/or |
| 8 | * modify it under the terms of the GNU Lesser General Public |
| 9 | * License as published by the Free Software Foundation; either |
| 10 | * version 2.1 of the License, or (at your option) any later version. |
| 11 | * |
| 12 | * FFmpeg is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| 15 | * Lesser General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU Lesser General Public |
| 18 | * License along with FFmpeg; if not, write to the Free Software |
| 19 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| 20 | */ |
| 21 | |
| 22 | #include "libavutil/channel_layout.h" |
| 23 | #include "libavutil/crc.h" |
| 24 | #include "libavutil/log.h" |
| 25 | #include "bytestream.h" |
| 26 | #include "get_bits.h" |
| 27 | #include "flac.h" |
| 28 | #include "flacdata.h" |
| 29 | |
| 30 | static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 }; |
| 31 | |
| 32 | static const uint64_t flac_channel_layouts[8] = { |
| 33 | AV_CH_LAYOUT_MONO, |
| 34 | AV_CH_LAYOUT_STEREO, |
| 35 | AV_CH_LAYOUT_SURROUND, |
| 36 | AV_CH_LAYOUT_QUAD, |
| 37 | AV_CH_LAYOUT_5POINT0, |
| 38 | AV_CH_LAYOUT_5POINT1, |
| 39 | AV_CH_LAYOUT_6POINT1, |
| 40 | AV_CH_LAYOUT_7POINT1 |
| 41 | }; |
| 42 | |
| 43 | static int64_t get_utf8(GetBitContext *gb) |
| 44 | { |
| 45 | int64_t val; |
| 46 | GET_UTF8(val, get_bits(gb, 8), return -1;) |
| 47 | return val; |
| 48 | } |
| 49 | |
| 50 | int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, |
| 51 | FLACFrameInfo *fi, int log_level_offset) |
| 52 | { |
| 53 | int bs_code, sr_code, bps_code; |
| 54 | |
| 55 | /* frame sync code */ |
| 56 | if ((get_bits(gb, 15) & 0x7FFF) != 0x7FFC) { |
| 57 | av_log(avctx, AV_LOG_ERROR + log_level_offset, "invalid sync code\n"); |
| 58 | return AVERROR_INVALIDDATA; |
| 59 | } |
| 60 | |
| 61 | /* variable block size stream code */ |
| 62 | fi->is_var_size = get_bits1(gb); |
| 63 | |
| 64 | /* block size and sample rate codes */ |
| 65 | bs_code = get_bits(gb, 4); |
| 66 | sr_code = get_bits(gb, 4); |
| 67 | |
| 68 | /* channels and decorrelation */ |
| 69 | fi->ch_mode = get_bits(gb, 4); |
| 70 | if (fi->ch_mode < FLAC_MAX_CHANNELS) { |
| 71 | fi->channels = fi->ch_mode + 1; |
| 72 | fi->ch_mode = FLAC_CHMODE_INDEPENDENT; |
| 73 | } else if (fi->ch_mode < FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE) { |
| 74 | fi->channels = 2; |
| 75 | fi->ch_mode -= FLAC_MAX_CHANNELS - 1; |
| 76 | } else { |
| 77 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 78 | "invalid channel mode: %d\n", fi->ch_mode); |
| 79 | return AVERROR_INVALIDDATA; |
| 80 | } |
| 81 | |
| 82 | /* bits per sample */ |
| 83 | bps_code = get_bits(gb, 3); |
| 84 | if (bps_code == 3 || bps_code == 7) { |
| 85 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 86 | "invalid sample size code (%d)\n", |
| 87 | bps_code); |
| 88 | return AVERROR_INVALIDDATA; |
| 89 | } |
| 90 | fi->bps = sample_size_table[bps_code]; |
| 91 | |
| 92 | /* reserved bit */ |
| 93 | if (get_bits1(gb)) { |
| 94 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 95 | "broken stream, invalid padding\n"); |
| 96 | return AVERROR_INVALIDDATA; |
| 97 | } |
| 98 | |
| 99 | /* sample or frame count */ |
| 100 | fi->frame_or_sample_num = get_utf8(gb); |
| 101 | if (fi->frame_or_sample_num < 0) { |
| 102 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 103 | "sample/frame number invalid; utf8 fscked\n"); |
| 104 | return AVERROR_INVALIDDATA; |
| 105 | } |
| 106 | |
| 107 | /* blocksize */ |
| 108 | if (bs_code == 0) { |
| 109 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 110 | "reserved blocksize code: 0\n"); |
| 111 | return AVERROR_INVALIDDATA; |
| 112 | } else if (bs_code == 6) { |
| 113 | fi->blocksize = get_bits(gb, 8) + 1; |
| 114 | } else if (bs_code == 7) { |
| 115 | fi->blocksize = get_bits(gb, 16) + 1; |
| 116 | } else { |
| 117 | fi->blocksize = ff_flac_blocksize_table[bs_code]; |
| 118 | } |
| 119 | |
| 120 | /* sample rate */ |
| 121 | if (sr_code < 12) { |
| 122 | fi->samplerate = ff_flac_sample_rate_table[sr_code]; |
| 123 | } else if (sr_code == 12) { |
| 124 | fi->samplerate = get_bits(gb, 8) * 1000; |
| 125 | } else if (sr_code == 13) { |
| 126 | fi->samplerate = get_bits(gb, 16); |
| 127 | } else if (sr_code == 14) { |
| 128 | fi->samplerate = get_bits(gb, 16) * 10; |
| 129 | } else { |
| 130 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 131 | "illegal sample rate code %d\n", |
| 132 | sr_code); |
| 133 | return AVERROR_INVALIDDATA; |
| 134 | } |
| 135 | |
| 136 | /* header CRC-8 check */ |
| 137 | skip_bits(gb, 8); |
| 138 | if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer, |
| 139 | get_bits_count(gb)/8)) { |
| 140 | av_log(avctx, AV_LOG_ERROR + log_level_offset, |
| 141 | "header crc mismatch\n"); |
| 142 | return AVERROR_INVALIDDATA; |
| 143 | } |
| 144 | |
| 145 | return 0; |
| 146 | } |
| 147 | |
| 148 | int ff_flac_get_max_frame_size(int blocksize, int ch, int bps) |
| 149 | { |
| 150 | /* Technically, there is no limit to FLAC frame size, but an encoder |
| 151 | should not write a frame that is larger than if verbatim encoding mode |
| 152 | were to be used. */ |
| 153 | |
| 154 | int count; |
| 155 | |
| 156 | count = 16; /* frame header */ |
| 157 | count += ch * ((7+bps+7)/8); /* subframe headers */ |
| 158 | if (ch == 2) { |
| 159 | /* for stereo, need to account for using decorrelation */ |
| 160 | count += (( 2*bps+1) * blocksize + 7) / 8; |
| 161 | } else { |
| 162 | count += ( ch*bps * blocksize + 7) / 8; |
| 163 | } |
| 164 | count += 2; /* frame footer */ |
| 165 | |
| 166 | return count; |
| 167 | } |
| 168 | |
| 169 | int ff_flac_is_extradata_valid(AVCodecContext *avctx, |
| 170 | enum FLACExtradataFormat *format, |
| 171 | uint8_t **streaminfo_start) |
| 172 | { |
| 173 | if (!avctx->extradata || avctx->extradata_size < FLAC_STREAMINFO_SIZE) { |
| 174 | av_log(avctx, AV_LOG_ERROR, "extradata NULL or too small.\n"); |
| 175 | return 0; |
| 176 | } |
| 177 | if (AV_RL32(avctx->extradata) != MKTAG('f','L','a','C')) { |
| 178 | /* extradata contains STREAMINFO only */ |
| 179 | if (avctx->extradata_size != FLAC_STREAMINFO_SIZE) { |
| 180 | av_log(avctx, AV_LOG_WARNING, "extradata contains %d bytes too many.\n", |
| 181 | FLAC_STREAMINFO_SIZE-avctx->extradata_size); |
| 182 | } |
| 183 | *format = FLAC_EXTRADATA_FORMAT_STREAMINFO; |
| 184 | *streaminfo_start = avctx->extradata; |
| 185 | } else { |
| 186 | if (avctx->extradata_size < 8+FLAC_STREAMINFO_SIZE) { |
| 187 | av_log(avctx, AV_LOG_ERROR, "extradata too small.\n"); |
| 188 | return 0; |
| 189 | } |
| 190 | *format = FLAC_EXTRADATA_FORMAT_FULL_HEADER; |
| 191 | *streaminfo_start = &avctx->extradata[8]; |
| 192 | } |
| 193 | return 1; |
| 194 | } |
| 195 | |
| 196 | void ff_flac_set_channel_layout(AVCodecContext *avctx) |
| 197 | { |
| 198 | if (avctx->channels <= FF_ARRAY_ELEMS(flac_channel_layouts)) |
| 199 | avctx->channel_layout = flac_channel_layouts[avctx->channels - 1]; |
| 200 | else |
| 201 | avctx->channel_layout = 0; |
| 202 | } |
| 203 | |
| 204 | void ff_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, |
| 205 | const uint8_t *buffer) |
| 206 | { |
| 207 | GetBitContext gb; |
| 208 | init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8); |
| 209 | |
| 210 | skip_bits(&gb, 16); /* skip min blocksize */ |
| 211 | s->max_blocksize = get_bits(&gb, 16); |
| 212 | if (s->max_blocksize < FLAC_MIN_BLOCKSIZE) { |
| 213 | av_log(avctx, AV_LOG_WARNING, "invalid max blocksize: %d\n", |
| 214 | s->max_blocksize); |
| 215 | s->max_blocksize = 16; |
| 216 | } |
| 217 | |
| 218 | skip_bits(&gb, 24); /* skip min frame size */ |
| 219 | s->max_framesize = get_bits_long(&gb, 24); |
| 220 | |
| 221 | s->samplerate = get_bits_long(&gb, 20); |
| 222 | s->channels = get_bits(&gb, 3) + 1; |
| 223 | s->bps = get_bits(&gb, 5) + 1; |
| 224 | |
| 225 | avctx->channels = s->channels; |
| 226 | avctx->sample_rate = s->samplerate; |
| 227 | avctx->bits_per_raw_sample = s->bps; |
| 228 | |
| 229 | if (!avctx->channel_layout || |
| 230 | av_get_channel_layout_nb_channels(avctx->channel_layout) != avctx->channels) |
| 231 | ff_flac_set_channel_layout(avctx); |
| 232 | |
| 233 | s->samples = get_bits64(&gb, 36); |
| 234 | |
| 235 | skip_bits_long(&gb, 64); /* md5 sum */ |
| 236 | skip_bits_long(&gb, 64); /* md5 sum */ |
| 237 | } |
| 238 | |
| 239 | #if LIBAVCODEC_VERSION_MAJOR < 57 |
| 240 | void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, |
| 241 | const uint8_t *buffer) |
| 242 | { |
| 243 | ff_flac_parse_streaminfo(avctx, s, buffer); |
| 244 | } |
| 245 | |
| 246 | int avpriv_flac_is_extradata_valid(AVCodecContext *avctx, |
| 247 | enum FLACExtradataFormat *format, |
| 248 | uint8_t **streaminfo_start) |
| 249 | { |
| 250 | return ff_flac_is_extradata_valid(avctx, format, streaminfo_start); |
| 251 | } |
| 252 | #endif |