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https://github.com/FFmpeg/FFmpeg.git
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a085cfa654
It is only used by demuxers (although it is hypothetically possible that some day e.g. a protocol might need it, but that is unlikely given that they don't deal with AVCodecParameters). Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
147 lines
4.1 KiB
C
147 lines
4.1 KiB
C
/*
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* Copyright (c) 2011 Justin Ruggles
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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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/**
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* @file
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* CRI ADX demuxer
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*/
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#include "libavutil/intreadwrite.h"
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#include "avformat.h"
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#include "demux.h"
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#include "internal.h"
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#define BLOCK_SIZE 18
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#define BLOCK_SAMPLES 32
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typedef struct ADXDemuxerContext {
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int header_size;
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} ADXDemuxerContext;
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static int adx_probe(const AVProbeData *p)
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{
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int offset;
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if (AV_RB16(p->buf) != 0x8000)
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return 0;
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offset = AV_RB16(&p->buf[2]);
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if ( offset < 8
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|| offset > p->buf_size - 4
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|| memcmp(p->buf + offset - 2, "(c)CRI", 6))
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return 0;
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return AVPROBE_SCORE_MAX * 3 / 4;
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}
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static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
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{
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ADXDemuxerContext *c = s->priv_data;
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AVCodecParameters *par = s->streams[0]->codecpar;
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int ret, size;
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if (avio_feof(s->pb))
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return AVERROR_EOF;
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if (par->ch_layout.nb_channels <= 0) {
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av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", par->ch_layout.nb_channels);
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return AVERROR_INVALIDDATA;
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}
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size = BLOCK_SIZE * par->ch_layout.nb_channels;
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pkt->pos = avio_tell(s->pb);
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pkt->stream_index = 0;
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ret = av_get_packet(s->pb, pkt, size * 128);
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if (ret < 0)
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return ret;
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if ((ret % size) && ret >= size) {
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size = ret - (ret % size);
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av_shrink_packet(pkt, size);
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pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
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} else if (ret < size) {
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return AVERROR(EIO);
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} else {
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size = ret;
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}
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pkt->duration = size / (BLOCK_SIZE * par->ch_layout.nb_channels);
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pkt->pts = (pkt->pos - c->header_size) / (BLOCK_SIZE * par->ch_layout.nb_channels);
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return 0;
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}
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static int adx_read_header(AVFormatContext *s)
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{
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ADXDemuxerContext *c = s->priv_data;
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AVCodecParameters *par;
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int ret;
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int channels;
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AVStream *st = avformat_new_stream(s, NULL);
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if (!st)
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return AVERROR(ENOMEM);
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par = s->streams[0]->codecpar;
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if (avio_rb16(s->pb) != 0x8000)
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return AVERROR_INVALIDDATA;
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c->header_size = avio_rb16(s->pb) + 4;
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avio_seek(s->pb, -4, SEEK_CUR);
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if ((ret = ff_get_extradata(s, par, s->pb, c->header_size)) < 0)
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return ret;
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if (par->extradata_size < 12) {
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av_log(s, AV_LOG_ERROR, "Invalid extradata size.\n");
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return AVERROR_INVALIDDATA;
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}
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channels = AV_RB8 (par->extradata + 7);
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par->sample_rate = AV_RB32(par->extradata + 8);
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if (channels <= 0) {
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av_log(s, AV_LOG_ERROR, "invalid number of channels %d\n", channels);
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return AVERROR_INVALIDDATA;
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}
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if (par->sample_rate <= 0) {
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av_log(s, AV_LOG_ERROR, "Invalid sample rate %d\n", par->sample_rate);
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return AVERROR_INVALIDDATA;
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}
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par->ch_layout.nb_channels = channels;
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par->codec_type = AVMEDIA_TYPE_AUDIO;
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par->codec_id = s->iformat->raw_codec_id;
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par->bit_rate = (int64_t)par->sample_rate * par->ch_layout.nb_channels * BLOCK_SIZE * 8LL / BLOCK_SAMPLES;
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avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, par->sample_rate);
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return 0;
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}
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const AVInputFormat ff_adx_demuxer = {
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.name = "adx",
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.long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
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.read_probe = adx_probe,
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.priv_data_size = sizeof(ADXDemuxerContext),
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.read_header = adx_read_header,
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.read_packet = adx_read_packet,
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.extensions = "adx",
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.raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
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.flags = AVFMT_GENERIC_INDEX,
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};
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