ffmpeg / libavformat / flacdec.c @ e4d2d8c5
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/*
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* Raw FLAC demuxer
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* Copyright (c) 2001 Fabrice Bellard
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*
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* This file is part of FFmpeg.
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*
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* FFmpeg is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* FFmpeg is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with FFmpeg; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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#include "libavcodec/flac.h" |
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#include "avformat.h" |
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#include "raw.h" |
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#include "id3v2.h" |
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#include "oggdec.h" |
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static int flac_read_header(AVFormatContext *s, |
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AVFormatParameters *ap) |
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{ |
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uint8_t buf[ID3v2_HEADER_SIZE]; |
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int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0; |
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uint8_t header[4];
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uint8_t *buffer=NULL;
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AVStream *st = av_new_stream(s, 0);
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if (!st)
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return AVERROR(ENOMEM);
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st->codec->codec_type = CODEC_TYPE_AUDIO; |
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st->codec->codec_id = CODEC_ID_FLAC; |
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st->need_parsing = AVSTREAM_PARSE_FULL; |
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/* the parameters will be extracted from the compressed bitstream */
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/* skip ID3v2 header if found */
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ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE); |
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if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) {
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int len = ff_id3v2_tag_len(buf);
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url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR); |
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} else {
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url_fseek(s->pb, 0, SEEK_SET);
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} |
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/* if fLaC marker is not found, assume there is no header */
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if (get_le32(s->pb) != MKTAG('f','L','a','C')) { |
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url_fseek(s->pb, -4, SEEK_CUR);
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return 0; |
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} |
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/* process metadata blocks */
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while (!url_feof(s->pb) && !metadata_last) {
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get_buffer(s->pb, header, 4);
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ff_flac_parse_block_header(header, &metadata_last, &metadata_type, |
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&metadata_size); |
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switch (metadata_type) {
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/* allocate and read metadata block for supported types */
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case FLAC_METADATA_TYPE_STREAMINFO:
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case FLAC_METADATA_TYPE_VORBIS_COMMENT:
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buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE); |
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if (!buffer) {
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return AVERROR_NOMEM;
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} |
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if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) {
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av_freep(&buffer); |
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return AVERROR_IO;
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} |
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break;
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/* skip metadata block for unsupported types */
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default:
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ret = url_fseek(s->pb, metadata_size, SEEK_CUR); |
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if (ret < 0) |
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return ret;
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} |
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if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
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FLACStreaminfo si; |
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/* STREAMINFO can only occur once */
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if (found_streaminfo) {
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av_freep(&buffer); |
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return AVERROR_INVALIDDATA;
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} |
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if (metadata_size != FLAC_STREAMINFO_SIZE) {
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av_freep(&buffer); |
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return AVERROR_INVALIDDATA;
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} |
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found_streaminfo = 1;
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st->codec->extradata = buffer; |
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st->codec->extradata_size = metadata_size; |
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buffer = NULL;
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/* get codec params from STREAMINFO header */
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ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata); |
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/* set time base and duration */
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if (si.samplerate > 0) { |
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av_set_pts_info(st, 64, 1, si.samplerate); |
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if (si.samples > 0) |
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st->duration = si.samples; |
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} |
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} else {
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/* STREAMINFO must be the first block */
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if (!found_streaminfo) {
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av_freep(&buffer); |
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return AVERROR_INVALIDDATA;
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} |
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/* process supported blocks other than STREAMINFO */
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if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
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if (ff_vorbis_comment(s, buffer, metadata_size)) {
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av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
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} |
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} |
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av_freep(&buffer); |
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} |
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} |
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return 0; |
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} |
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static int flac_probe(AVProbeData *p) |
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{ |
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uint8_t *bufptr = p->buf; |
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uint8_t *end = p->buf + p->buf_size; |
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if(ff_id3v2_match(bufptr))
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bufptr += ff_id3v2_tag_len(bufptr); |
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if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0; |
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else return AVPROBE_SCORE_MAX/2; |
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} |
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AVInputFormat flac_demuxer = { |
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"flac",
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NULL_IF_CONFIG_SMALL("raw FLAC"),
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0,
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flac_probe, |
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flac_read_header, |
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ff_raw_read_partial_packet, |
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.flags= AVFMT_GENERIC_INDEX, |
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.extensions = "flac",
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.value = CODEC_ID_FLAC, |
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.metadata_conv = ff_vorbiscomment_metadata_conv, |
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}; |