yading@10: /* yading@10: * FLAC common code yading@10: * Copyright (c) 2009 Justin Ruggles yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: #include "libavutil/channel_layout.h" yading@10: #include "libavutil/crc.h" yading@10: #include "libavutil/log.h" yading@10: #include "bytestream.h" yading@10: #include "get_bits.h" yading@10: #include "flac.h" yading@10: #include "flacdata.h" yading@10: yading@10: static const int8_t sample_size_table[] = { 0, 8, 12, 0, 16, 20, 24, 0 }; yading@10: yading@10: static const uint64_t flac_channel_layouts[8] = { yading@10: AV_CH_LAYOUT_MONO, yading@10: AV_CH_LAYOUT_STEREO, yading@10: AV_CH_LAYOUT_SURROUND, yading@10: AV_CH_LAYOUT_QUAD, yading@10: AV_CH_LAYOUT_5POINT0, yading@10: AV_CH_LAYOUT_5POINT1, yading@10: AV_CH_LAYOUT_6POINT1, yading@10: AV_CH_LAYOUT_7POINT1 yading@10: }; yading@10: yading@10: static int64_t get_utf8(GetBitContext *gb) yading@10: { yading@10: int64_t val; yading@10: GET_UTF8(val, get_bits(gb, 8), return -1;) yading@10: return val; yading@10: } yading@10: yading@10: int ff_flac_decode_frame_header(AVCodecContext *avctx, GetBitContext *gb, yading@10: FLACFrameInfo *fi, int log_level_offset) yading@10: { yading@10: int bs_code, sr_code, bps_code; yading@10: yading@10: /* frame sync code */ yading@10: if ((get_bits(gb, 15) & 0x7FFF) != 0x7FFC) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, "invalid sync code\n"); yading@10: return -1; yading@10: } yading@10: yading@10: /* variable block size stream code */ yading@10: fi->is_var_size = get_bits1(gb); yading@10: yading@10: /* block size and sample rate codes */ yading@10: bs_code = get_bits(gb, 4); yading@10: sr_code = get_bits(gb, 4); yading@10: yading@10: /* channels and decorrelation */ yading@10: fi->ch_mode = get_bits(gb, 4); yading@10: if (fi->ch_mode < FLAC_MAX_CHANNELS) { yading@10: fi->channels = fi->ch_mode + 1; yading@10: fi->ch_mode = FLAC_CHMODE_INDEPENDENT; yading@10: } else if (fi->ch_mode < FLAC_MAX_CHANNELS + FLAC_CHMODE_MID_SIDE) { yading@10: fi->channels = 2; yading@10: fi->ch_mode -= FLAC_MAX_CHANNELS - 1; yading@10: } else { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "invalid channel mode: %d\n", fi->ch_mode); yading@10: return -1; yading@10: } yading@10: yading@10: /* bits per sample */ yading@10: bps_code = get_bits(gb, 3); yading@10: if (bps_code == 3 || bps_code == 7) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "invalid sample size code (%d)\n", yading@10: bps_code); yading@10: return -1; yading@10: } yading@10: fi->bps = sample_size_table[bps_code]; yading@10: yading@10: /* reserved bit */ yading@10: if (get_bits1(gb)) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "broken stream, invalid padding\n"); yading@10: return -1; yading@10: } yading@10: yading@10: /* sample or frame count */ yading@10: fi->frame_or_sample_num = get_utf8(gb); yading@10: if (fi->frame_or_sample_num < 0) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "sample/frame number invalid; utf8 fscked\n"); yading@10: return -1; yading@10: } yading@10: yading@10: /* blocksize */ yading@10: if (bs_code == 0) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "reserved blocksize code: 0\n"); yading@10: return -1; yading@10: } else if (bs_code == 6) { yading@10: fi->blocksize = get_bits(gb, 8) + 1; yading@10: } else if (bs_code == 7) { yading@10: fi->blocksize = get_bits(gb, 16) + 1; yading@10: } else { yading@10: fi->blocksize = ff_flac_blocksize_table[bs_code]; yading@10: } yading@10: yading@10: /* sample rate */ yading@10: if (sr_code < 12) { yading@10: fi->samplerate = ff_flac_sample_rate_table[sr_code]; yading@10: } else if (sr_code == 12) { yading@10: fi->samplerate = get_bits(gb, 8) * 1000; yading@10: } else if (sr_code == 13) { yading@10: fi->samplerate = get_bits(gb, 16); yading@10: } else if (sr_code == 14) { yading@10: fi->samplerate = get_bits(gb, 16) * 10; yading@10: } else { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "illegal sample rate code %d\n", yading@10: sr_code); yading@10: return -1; yading@10: } yading@10: yading@10: /* header CRC-8 check */ yading@10: skip_bits(gb, 8); yading@10: if (av_crc(av_crc_get_table(AV_CRC_8_ATM), 0, gb->buffer, yading@10: get_bits_count(gb)/8)) { yading@10: av_log(avctx, AV_LOG_ERROR + log_level_offset, yading@10: "header crc mismatch\n"); yading@10: return -1; yading@10: } yading@10: yading@10: return 0; yading@10: } yading@10: yading@10: int ff_flac_get_max_frame_size(int blocksize, int ch, int bps) yading@10: { yading@10: /* Technically, there is no limit to FLAC frame size, but an encoder yading@10: should not write a frame that is larger than if verbatim encoding mode yading@10: were to be used. */ yading@10: yading@10: int count; yading@10: yading@10: count = 16; /* frame header */ yading@10: count += ch * ((7+bps+7)/8); /* subframe headers */ yading@10: if (ch == 2) { yading@10: /* for stereo, need to account for using decorrelation */ yading@10: count += (( 2*bps+1) * blocksize + 7) / 8; yading@10: } else { yading@10: count += ( ch*bps * blocksize + 7) / 8; yading@10: } yading@10: count += 2; /* frame footer */ yading@10: yading@10: return count; yading@10: } yading@10: yading@10: int avpriv_flac_is_extradata_valid(AVCodecContext *avctx, yading@10: enum FLACExtradataFormat *format, yading@10: uint8_t **streaminfo_start) yading@10: { yading@10: if (!avctx->extradata || avctx->extradata_size < FLAC_STREAMINFO_SIZE) { yading@10: av_log(avctx, AV_LOG_ERROR, "extradata NULL or too small.\n"); yading@10: return 0; yading@10: } yading@10: if (AV_RL32(avctx->extradata) != MKTAG('f','L','a','C')) { yading@10: /* extradata contains STREAMINFO only */ yading@10: if (avctx->extradata_size != FLAC_STREAMINFO_SIZE) { yading@10: av_log(avctx, AV_LOG_WARNING, "extradata contains %d bytes too many.\n", yading@10: FLAC_STREAMINFO_SIZE-avctx->extradata_size); yading@10: } yading@10: *format = FLAC_EXTRADATA_FORMAT_STREAMINFO; yading@10: *streaminfo_start = avctx->extradata; yading@10: } else { yading@10: if (avctx->extradata_size < 8+FLAC_STREAMINFO_SIZE) { yading@10: av_log(avctx, AV_LOG_ERROR, "extradata too small.\n"); yading@10: return 0; yading@10: } yading@10: *format = FLAC_EXTRADATA_FORMAT_FULL_HEADER; yading@10: *streaminfo_start = &avctx->extradata[8]; yading@10: } yading@10: return 1; yading@10: } yading@10: yading@10: void ff_flac_set_channel_layout(AVCodecContext *avctx) yading@10: { yading@10: if (avctx->channels <= FF_ARRAY_ELEMS(flac_channel_layouts)) yading@10: avctx->channel_layout = flac_channel_layouts[avctx->channels - 1]; yading@10: else yading@10: avctx->channel_layout = 0; yading@10: } yading@10: yading@10: void avpriv_flac_parse_streaminfo(AVCodecContext *avctx, struct FLACStreaminfo *s, yading@10: const uint8_t *buffer) yading@10: { yading@10: GetBitContext gb; yading@10: init_get_bits(&gb, buffer, FLAC_STREAMINFO_SIZE*8); yading@10: yading@10: skip_bits(&gb, 16); /* skip min blocksize */ yading@10: s->max_blocksize = get_bits(&gb, 16); yading@10: if (s->max_blocksize < FLAC_MIN_BLOCKSIZE) { yading@10: av_log(avctx, AV_LOG_WARNING, "invalid max blocksize: %d\n", yading@10: s->max_blocksize); yading@10: s->max_blocksize = 16; yading@10: } yading@10: yading@10: skip_bits(&gb, 24); /* skip min frame size */ yading@10: s->max_framesize = get_bits_long(&gb, 24); yading@10: yading@10: s->samplerate = get_bits_long(&gb, 20); yading@10: s->channels = get_bits(&gb, 3) + 1; yading@10: s->bps = get_bits(&gb, 5) + 1; yading@10: yading@10: avctx->channels = s->channels; yading@10: avctx->sample_rate = s->samplerate; yading@10: avctx->bits_per_raw_sample = s->bps; yading@10: ff_flac_set_channel_layout(avctx); yading@10: yading@10: s->samples = get_bits64(&gb, 36); yading@10: yading@10: skip_bits_long(&gb, 64); /* md5 sum */ yading@10: skip_bits_long(&gb, 64); /* md5 sum */ yading@10: } yading@10: yading@10: void avpriv_flac_parse_block_header(const uint8_t *block_header, yading@10: int *last, int *type, int *size) yading@10: { yading@10: int tmp = bytestream_get_byte(&block_header); yading@10: if (last) yading@10: *last = tmp & 0x80; yading@10: if (type) yading@10: *type = tmp & 0x7F; yading@10: if (size) yading@10: *size = bytestream_get_be24(&block_header); yading@10: }