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00026 #include "libavutil/intreadwrite.h"
00027 #include "libavcodec/adx.h"
00028 #include "avformat.h"
00029 #include "internal.h"
00030
00031 #define BLOCK_SIZE 18
00032 #define BLOCK_SAMPLES 32
00033
00034 typedef struct ADXDemuxerContext {
00035 int header_size;
00036 } ADXDemuxerContext;
00037
00038 static int adx_read_packet(AVFormatContext *s, AVPacket *pkt)
00039 {
00040 ADXDemuxerContext *c = s->priv_data;
00041 AVCodecContext *avctx = s->streams[0]->codec;
00042 int ret, size;
00043
00044 size = BLOCK_SIZE * avctx->channels;
00045
00046 pkt->pos = avio_tell(s->pb);
00047 pkt->stream_index = 0;
00048
00049 ret = av_get_packet(s->pb, pkt, size);
00050 if (ret != size) {
00051 av_free_packet(pkt);
00052 return ret < 0 ? ret : AVERROR(EIO);
00053 }
00054 if (AV_RB16(pkt->data) & 0x8000) {
00055 av_free_packet(pkt);
00056 return AVERROR_EOF;
00057 }
00058 pkt->size = size;
00059 pkt->duration = 1;
00060 pkt->pts = (pkt->pos - c->header_size) / size;
00061
00062 return 0;
00063 }
00064
00065 static int adx_read_header(AVFormatContext *s)
00066 {
00067 ADXDemuxerContext *c = s->priv_data;
00068 AVCodecContext *avctx;
00069 int ret;
00070
00071 AVStream *st = avformat_new_stream(s, NULL);
00072 if (!st)
00073 return AVERROR(ENOMEM);
00074 avctx = s->streams[0]->codec;
00075
00076 if (avio_rb16(s->pb) != 0x8000)
00077 return AVERROR_INVALIDDATA;
00078 c->header_size = avio_rb16(s->pb) + 4;
00079 avio_seek(s->pb, -4, SEEK_CUR);
00080
00081 avctx->extradata = av_mallocz(c->header_size + FF_INPUT_BUFFER_PADDING_SIZE);
00082 if (!avctx->extradata)
00083 return AVERROR(ENOMEM);
00084 if (avio_read(s->pb, avctx->extradata, c->header_size) < c->header_size) {
00085 av_freep(&avctx->extradata);
00086 return AVERROR(EIO);
00087 }
00088 avctx->extradata_size = c->header_size;
00089
00090 ret = avpriv_adx_decode_header(avctx, avctx->extradata,
00091 avctx->extradata_size, &c->header_size,
00092 NULL);
00093 if (ret)
00094 return ret;
00095
00096 st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
00097 st->codec->codec_id = s->iformat->raw_codec_id;
00098
00099 avpriv_set_pts_info(st, 64, BLOCK_SAMPLES, avctx->sample_rate);
00100
00101 return 0;
00102 }
00103
00104 AVInputFormat ff_adx_demuxer = {
00105 .name = "adx",
00106 .long_name = NULL_IF_CONFIG_SMALL("CRI ADX"),
00107 .priv_data_size = sizeof(ADXDemuxerContext),
00108 .read_header = adx_read_header,
00109 .read_packet = adx_read_packet,
00110 .extensions = "adx",
00111 .raw_codec_id = AV_CODEC_ID_ADPCM_ADX,
00112 .flags = AVFMT_GENERIC_INDEX,
00113 };