/* * AST demuxer * Copyright (c) 2012 Paul B Mahol * * This file is part of FFmpeg. * * FFmpeg 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, * 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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include "libavutil/channel_layout.h"#include "libavutil/intreadwrite.h"#include "avformat.h"#include "internal.h"#include "ast.h" static int ast_probe(AVProbeData *p){    if (AV_RL32(p->buf) != MKTAG('S','T','R','M'))        return 0;     if (!AV_RB16(p->buf + 10) ||        !AV_RB16(p->buf + 12) || AV_RB16(p->buf + 12) > 256 ||        !AV_RB32(p->buf + 16) || AV_RB32(p->buf + 16) > 8*48000)        return AVPROBE_SCORE_MAX / 8;     return AVPROBE_SCORE_MAX / 3 * 2;} static int ast_read_header(AVFormatContext *s){    int depth;    AVStream *st;     st = avformat_new_stream(s, NULL);    if (!st)        return AVERROR(ENOMEM);     avio_skip(s->pb, 8);    st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;    st->codecpar->codec_id   = ff_codec_get_id(ff_codec_ast_tags, avio_rb16(s->pb));     depth = avio_rb16(s->pb);    if (depth != 16) {        avpriv_request_sample(s, "depth %d", depth);        return AVERROR_INVALIDDATA;    }     st->codecpar->channels = avio_rb16(s->pb);    if (!st->codecpar->channels)        return AVERROR_INVALIDDATA;     if (st->codecpar->channels == 2)        st->codecpar->channel_layout = AV_CH_LAYOUT_STEREO;    else if (st->codecpar->channels == 4)        st->codecpar->channel_layout = AV_CH_LAYOUT_4POINT0;     avio_skip(s->pb, 2);    st->codecpar->sample_rate = avio_rb32(s->pb);    if (st->codecpar->sample_rate <= 0)        return AVERROR_INVALIDDATA;    st->start_time         = 0;    st->duration           = avio_rb32(s->pb);    avio_skip(s->pb, 40);    avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);     return 0;} static int ast_read_packet(AVFormatContext *s, AVPacket *pkt){    uint32_t type, size;    int64_t pos;    int ret;     if (avio_feof(s->pb))        return AVERROR_EOF;     pos  = avio_tell(s->pb);    type = avio_rl32(s->pb);    size = avio_rb32(s->pb);    if (!s->streams[0]->codecpar->channels || size > INT_MAX / s->streams[0]->codecpar->channels)        return AVERROR_INVALIDDATA;     size *= s->streams[0]->codecpar->channels;    if ((ret = avio_skip(s->pb, 24)) < 0) // padding        return ret;     if (type == MKTAG('B','L','C','K')) {        ret = av_get_packet(s->pb, pkt, size);        pkt->stream_index = 0;        pkt->pos = pos;    } else {        av_log(s, AV_LOG_ERROR, "unknown chunk %"PRIx32"\n", type);        avio_skip(s->pb, size);        ret = AVERROR_INVALIDDATA;    }     return ret;} AVInputFormat ff_ast_demuxer = {    .name           = "ast",    .long_name      = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),    .read_probe     = ast_probe,    .read_header    = ast_read_header,    .read_packet    = ast_read_packet,    .extensions     = "ast",    .flags          = AVFMT_GENERIC_INDEX,    .codec_tag      = (const AVCodecTag* const []){ff_codec_ast_tags, 0},};