X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=libavcodec%2Fac3_parser.c;h=53189e0d4ed793464ff01d0f6bd7d2c96542365b;hb=8f144d9e3d5cb2ca92e5bdf7cc9f72effa1bd2ce;hp=d97c86e01b0fbe29b99951cd999949d88ef9181b;hpb=3df880934e721d7e37e4feb1d4a3f226cfc1bf2d;p=ffmpeg diff --git a/libavcodec/ac3_parser.c b/libavcodec/ac3_parser.c index d97c86e01b0..53189e0d4ed 100644 --- a/libavcodec/ac3_parser.c +++ b/libavcodec/ac3_parser.c @@ -1,162 +1,228 @@ /* - * AC3 parser - * Copyright (c) 2003 Fabrice Bellard. - * Copyright (c) 2003 Michael Niedermayer. + * AC-3 parser + * Copyright (c) 2003 Fabrice Bellard + * Copyright (c) 2003 Michael Niedermayer * - * This file is part of FFmpeg. + * This file is part of Libav. * - * FFmpeg is free software; you can redistribute it and/or + * Libav is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * - * FFmpeg is distributed in the hope that it will be useful, + * Libav is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software + * License along with Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ +#include "config.h" + +#include "libavutil/channel_layout.h" #include "parser.h" #include "ac3_parser.h" +#include "ac3_parser_internal.h" #include "aac_ac3_parser.h" -#include "bitstream.h" +#include "get_bits.h" #define AC3_HEADER_SIZE 7 +#if CONFIG_AC3_PARSER static const uint8_t eac3_blocks[4] = { 1, 2, 3, 6 }; +/** + * Table for center mix levels + * reference: Section 5.4.2.4 cmixlev + */ +static const uint8_t center_levels[4] = { 4, 5, 6, 5 }; + +/** + * Table for surround mix levels + * reference: Section 5.4.2.5 surmixlev + */ +static const uint8_t surround_levels[4] = { 4, 6, 7, 6 }; + -int ff_ac3_parse_header(const uint8_t buf[7], AC3HeaderInfo *hdr) +int ff_ac3_parse_header(GetBitContext *gbc, AC3HeaderInfo *hdr) { - GetBitContext gbc; + int frame_size_code; memset(hdr, 0, sizeof(*hdr)); - init_get_bits(&gbc, buf, 54); - - hdr->sync_word = get_bits(&gbc, 16); + hdr->sync_word = get_bits(gbc, 16); if(hdr->sync_word != 0x0B77) - return AC3_PARSE_ERROR_SYNC; + return AAC_AC3_PARSE_ERROR_SYNC; - /* read ahead to bsid to make sure this is AC-3, not E-AC-3 */ - hdr->bsid = show_bits_long(&gbc, 29) & 0x1F; - if(hdr->bsid > 10) - return AC3_PARSE_ERROR_BSID; + /* read ahead to bsid to distinguish between AC-3 and E-AC-3 */ + hdr->bitstream_id = show_bits_long(gbc, 29) & 0x1F; + if(hdr->bitstream_id > 16) + return AAC_AC3_PARSE_ERROR_BSID; - hdr->crc1 = get_bits(&gbc, 16); - hdr->fscod = get_bits(&gbc, 2); - if(hdr->fscod == 3) - return AC3_PARSE_ERROR_SAMPLE_RATE; + hdr->num_blocks = 6; - hdr->frmsizecod = get_bits(&gbc, 6); - if(hdr->frmsizecod > 37) - return AC3_PARSE_ERROR_FRAME_SIZE; + /* set default mix levels */ + hdr->center_mix_level = 5; // -4.5dB + hdr->surround_mix_level = 6; // -6.0dB - skip_bits(&gbc, 5); // skip bsid, already got it + /* set default dolby surround mode */ + hdr->dolby_surround_mode = AC3_DSURMOD_NOTINDICATED; - hdr->bsmod = get_bits(&gbc, 3); - hdr->acmod = get_bits(&gbc, 3); - if((hdr->acmod & 1) && hdr->acmod != AC3_ACMOD_MONO) { - hdr->cmixlev = get_bits(&gbc, 2); - } - if(hdr->acmod & 4) { - hdr->surmixlev = get_bits(&gbc, 2); - } - if(hdr->acmod == AC3_ACMOD_STEREO) { - hdr->dsurmod = get_bits(&gbc, 2); - } - hdr->lfeon = get_bits1(&gbc); + if(hdr->bitstream_id <= 10) { + /* Normal AC-3 */ + hdr->crc1 = get_bits(gbc, 16); + hdr->sr_code = get_bits(gbc, 2); + if(hdr->sr_code == 3) + return AAC_AC3_PARSE_ERROR_SAMPLE_RATE; - hdr->halfratecod = FFMAX(hdr->bsid, 8) - 8; - hdr->sample_rate = ff_ac3_freqs[hdr->fscod] >> hdr->halfratecod; - hdr->bit_rate = (ff_ac3_bitratetab[hdr->frmsizecod>>1] * 1000) >> hdr->halfratecod; - hdr->channels = ff_ac3_channels[hdr->acmod] + hdr->lfeon; - hdr->frame_size = ff_ac3_frame_sizes[hdr->frmsizecod][hdr->fscod] * 2; + frame_size_code = get_bits(gbc, 6); + if(frame_size_code > 37) + return AAC_AC3_PARSE_ERROR_FRAME_SIZE; + + skip_bits(gbc, 5); // skip bsid, already got it + + hdr->bitstream_mode = get_bits(gbc, 3); + hdr->channel_mode = get_bits(gbc, 3); + + if(hdr->channel_mode == AC3_CHMODE_STEREO) { + hdr->dolby_surround_mode = get_bits(gbc, 2); + } else { + if((hdr->channel_mode & 1) && hdr->channel_mode != AC3_CHMODE_MONO) + hdr-> center_mix_level = center_levels[get_bits(gbc, 2)]; + if(hdr->channel_mode & 4) + hdr->surround_mix_level = surround_levels[get_bits(gbc, 2)]; + } + hdr->lfe_on = get_bits1(gbc); + + hdr->sr_shift = FFMAX(hdr->bitstream_id, 8) - 8; + hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code] >> hdr->sr_shift; + hdr->bit_rate = (ff_ac3_bitrate_tab[frame_size_code>>1] * 1000) >> hdr->sr_shift; + hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on; + hdr->frame_size = ff_ac3_frame_size_tab[frame_size_code][hdr->sr_code] * 2; + hdr->frame_type = EAC3_FRAME_TYPE_AC3_CONVERT; //EAC3_FRAME_TYPE_INDEPENDENT; + hdr->substreamid = 0; + } else { + /* Enhanced AC-3 */ + hdr->crc1 = 0; + hdr->frame_type = get_bits(gbc, 2); + if(hdr->frame_type == EAC3_FRAME_TYPE_RESERVED) + return AAC_AC3_PARSE_ERROR_FRAME_TYPE; + + hdr->substreamid = get_bits(gbc, 3); + + hdr->frame_size = (get_bits(gbc, 11) + 1) << 1; + if(hdr->frame_size < AC3_HEADER_SIZE) + return AAC_AC3_PARSE_ERROR_FRAME_SIZE; + + hdr->sr_code = get_bits(gbc, 2); + if (hdr->sr_code == 3) { + int sr_code2 = get_bits(gbc, 2); + if(sr_code2 == 3) + return AAC_AC3_PARSE_ERROR_SAMPLE_RATE; + hdr->sample_rate = ff_ac3_sample_rate_tab[sr_code2] / 2; + hdr->sr_shift = 1; + } else { + hdr->num_blocks = eac3_blocks[get_bits(gbc, 2)]; + hdr->sample_rate = ff_ac3_sample_rate_tab[hdr->sr_code]; + hdr->sr_shift = 0; + } + + hdr->channel_mode = get_bits(gbc, 3); + hdr->lfe_on = get_bits1(gbc); + + hdr->bit_rate = (uint32_t)(8.0 * hdr->frame_size * hdr->sample_rate / + (hdr->num_blocks * 256.0)); + hdr->channels = ff_ac3_channels_tab[hdr->channel_mode] + hdr->lfe_on; + } + hdr->channel_layout = avpriv_ac3_channel_layout_tab[hdr->channel_mode]; + if (hdr->lfe_on) + hdr->channel_layout |= AV_CH_LOW_FREQUENCY; return 0; } -static int ac3_sync(const uint8_t *buf, int *channels, int *sample_rate, - int *bit_rate, int *samples) +int av_ac3_parse_header(const uint8_t *buf, size_t size, + uint8_t *bitstream_id, uint16_t *frame_size) { - int err; - unsigned int fscod, acmod, bsid, lfeon; - unsigned int strmtyp, substreamid, frmsiz, fscod2, numblkscod; - GetBitContext bits; + GetBitContext gb; AC3HeaderInfo hdr; + int err; - err = ff_ac3_parse_header(buf, &hdr); + init_get_bits8(&gb, buf, size); + err = ff_ac3_parse_header(&gb, &hdr); + if (err < 0) + return AVERROR_INVALIDDATA; - if(err < 0 && err != -2) - return 0; - - bsid = hdr.bsid; - if(bsid <= 10) { /* Normal AC-3 */ - *sample_rate = hdr.sample_rate; - *bit_rate = hdr.bit_rate; - *channels = hdr.channels; - *samples = AC3_FRAME_SIZE; - return hdr.frame_size; - } else if (bsid > 10 && bsid <= 16) { /* Enhanced AC-3 */ - init_get_bits(&bits, &buf[2], (AC3_HEADER_SIZE-2) * 8); - strmtyp = get_bits(&bits, 2); - substreamid = get_bits(&bits, 3); - - if (strmtyp != 0 || substreamid != 0) - return 0; /* Currently don't support additional streams */ - - frmsiz = get_bits(&bits, 11) + 1; - fscod = get_bits(&bits, 2); - if (fscod == 3) { - fscod2 = get_bits(&bits, 2); - numblkscod = 3; - - if(fscod2 == 3) - return 0; - - *sample_rate = ff_ac3_freqs[fscod2] / 2; - } else { - numblkscod = get_bits(&bits, 2); + *bitstream_id = hdr.bitstream_id; + *frame_size = hdr.frame_size; - *sample_rate = ff_ac3_freqs[fscod]; - } + return 0; +} - acmod = get_bits(&bits, 3); - lfeon = get_bits1(&bits); +static int ac3_sync(uint64_t state, AACAC3ParseContext *hdr_info, + int *need_next_header, int *new_frame_start) +{ + int err; + union { + uint64_t u64; + uint8_t u8[8 + AV_INPUT_BUFFER_PADDING_SIZE]; + } tmp = { av_be2ne64(state) }; + AC3HeaderInfo hdr; + GetBitContext gbc; - *samples = eac3_blocks[numblkscod] * 256; - *bit_rate = frmsiz * (*sample_rate) * 16 / (*samples); - *channels = ff_ac3_channels[acmod] + lfeon; + init_get_bits(&gbc, tmp.u8+8-AC3_HEADER_SIZE, 54); + err = ff_ac3_parse_header(&gbc, &hdr); - return frmsiz * 2; - } + if(err < 0) + return 0; - /* Unsupported bitstream version */ - return 0; + hdr_info->sample_rate = hdr.sample_rate; + hdr_info->bit_rate = hdr.bit_rate; + hdr_info->channels = hdr.channels; + hdr_info->channel_layout = hdr.channel_layout; + hdr_info->samples = hdr.num_blocks * 256; + hdr_info->service_type = hdr.bitstream_mode; + if (hdr.bitstream_mode == 0x7 && hdr.channels > 1) + hdr_info->service_type = AV_AUDIO_SERVICE_TYPE_KARAOKE; + if(hdr.bitstream_id>10) + hdr_info->codec_id = AV_CODEC_ID_EAC3; + else if (hdr_info->codec_id == AV_CODEC_ID_NONE) + hdr_info->codec_id = AV_CODEC_ID_AC3; + + *need_next_header = (hdr.frame_type != EAC3_FRAME_TYPE_AC3_CONVERT); + *new_frame_start = (hdr.frame_type != EAC3_FRAME_TYPE_DEPENDENT); + return hdr.frame_size; } -static int ac3_parse_init(AVCodecParserContext *s1) +static av_cold int ac3_parse_init(AVCodecParserContext *s1) { AACAC3ParseContext *s = s1->priv_data; - s->inbuf_ptr = s->inbuf; s->header_size = AC3_HEADER_SIZE; s->sync = ac3_sync; return 0; } -AVCodecParser ac3_parser = { - { CODEC_ID_AC3 }, - sizeof(AACAC3ParseContext), - ac3_parse_init, - ff_aac_ac3_parse, - NULL, +AVCodecParser ff_ac3_parser = { + .codec_ids = { AV_CODEC_ID_AC3, AV_CODEC_ID_EAC3 }, + .priv_data_size = sizeof(AACAC3ParseContext), + .parser_init = ac3_parse_init, + .parser_parse = ff_aac_ac3_parse, + .parser_close = ff_parse_close, }; + +#else + +int av_ac3_parse_header(const uint8_t *buf, size_t size, + uint8_t *bitstream_id, uint16_t *frame_size) +{ + return AVERROR(ENOSYS); +} +#endif