*/
/**
- * @file mtv.c
+ * @file libavformat/mtv.c
* MTV demuxer.
*/
+#include "libavutil/bswap.h"
+#include "libavutil/intreadwrite.h"
#include "avformat.h"
-#include "bswap.h"
#define MTV_ASUBCHUNK_DATA_SIZE 500
#define MTV_HEADER_SIZE 512
typedef struct MTVDemuxContext {
- unsigned int file_size; ///< filesize, not always right
- unsigned int segments; ///< number of 512 byte segments
- unsigned int audio_identifier; ///< 'MP3' on all files I have seen
- unsigned int audio_br; ///< bitrate of audio chanel (mp3)
- unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
- unsigned int img_bpp; ///< frame bits per pixel
- unsigned int img_width; //
- unsigned int img_height; //
- unsigned int img_segment_size; ///< size of image segment
- unsigned int video_fps; //
- unsigned int audio_subsegments; ///< audio subsegments on one segment
-
- uint8_t audio_packet_count;
+ unsigned int file_size; ///< filesize, not always right
+ unsigned int segments; ///< number of 512 byte segments
+ unsigned int audio_identifier; ///< 'MP3' on all files I have seen
+ unsigned int audio_br; ///< bitrate of audio channel (mp3)
+ unsigned int img_colorfmt; ///< frame colorfmt rgb 565/555
+ unsigned int img_bpp; ///< frame bits per pixel
+ unsigned int img_width; //
+ unsigned int img_height; //
+ unsigned int img_segment_size; ///< size of image segment
+ unsigned int video_fps; //
+ unsigned int full_segment_size;
} MTVDemuxContext;
static int mtv_probe(AVProbeData *p)
{
/* Magic is 'AMV' */
-
if(*(p->buf) != 'A' || *(p->buf+1) != 'M' || *(p->buf+2) != 'V')
return 0;
+ /* Check for nonzero in bpp and (width|height) header fields */
+ if(!(p->buf[51] && AV_RL16(&p->buf[52]) | AV_RL16(&p->buf[54])))
+ return 0;
+
+ /* If width or height are 0 then imagesize header field should not */
+ if(!AV_RL16(&p->buf[52]) || !AV_RL16(&p->buf[54]))
+ {
+ if(!!AV_RL16(&p->buf[56]))
+ return AVPROBE_SCORE_MAX/2;
+ else
+ return 0;
+ }
+
+ if(p->buf[51] != 16)
+ return AVPROBE_SCORE_MAX/4; // But we are going to assume 16bpp anyway ..
+
return AVPROBE_SCORE_MAX;
}
static int mtv_read_header(AVFormatContext *s, AVFormatParameters *ap)
{
- MTVDemuxContext *mtv = s->priv_data;
- ByteIOContext *pb = &s->pb;
- AVStream *st;
-
+ MTVDemuxContext *mtv = s->priv_data;
+ ByteIOContext *pb = s->pb;
+ AVStream *st;
+ unsigned int audio_subsegments;
url_fskip(pb, 3);
mtv->file_size = get_le32(pb);
mtv->img_width = get_le16(pb);
mtv->img_height = get_le16(pb);
mtv->img_segment_size = get_le16(pb);
- url_fskip(pb, 4);
- mtv->audio_subsegments = get_le16(pb);
- mtv->video_fps = (mtv->audio_br / 4) / mtv->audio_subsegments;
- /* FIXME Add sanity check here */
+ /* Calculate width and height if missing from header */
- /* first packet is always audio*/
+ if(!mtv->img_width)
+ mtv->img_width=mtv->img_segment_size / (mtv->img_bpp>>3)
+ / mtv->img_height;
- mtv->audio_packet_count = 1;
+ if(!mtv->img_height)
+ mtv->img_height=mtv->img_segment_size / (mtv->img_bpp>>3)
+ / mtv->img_width;
- /* all systems go! init decoders */
+ url_fskip(pb, 4);
+ audio_subsegments = get_le16(pb);
+ mtv->full_segment_size =
+ audio_subsegments * (MTV_AUDIO_PADDING_SIZE + MTV_ASUBCHUNK_DATA_SIZE) +
+ mtv->img_segment_size;
+ mtv->video_fps = (mtv->audio_br / 4) / audio_subsegments;
- /* video - raw rgb565 */
+ // FIXME Add sanity check here
+
+ // all systems go! init decoders
+
+ // video - raw rgb565
st = av_new_stream(s, VIDEO_SID);
if(!st)
st->codec->codec_tag = MKTAG('R', 'G', 'B', mtv->img_bpp);
st->codec->width = mtv->img_width;
st->codec->height = mtv->img_height;
- st->codec->bits_per_sample = mtv->img_bpp;
+ st->codec->bits_per_coded_sample = mtv->img_bpp;
st->codec->sample_rate = mtv->video_fps;
+ st->codec->extradata = av_strdup("BottomUp");
+ st->codec->extradata_size = 9;
- /* audio - mp3 */
+ // audio - mp3
st = av_new_stream(s, AUDIO_SID);
if(!st)
st->codec->bit_rate = mtv->audio_br;
st->need_parsing = AVSTREAM_PARSE_FULL;
- /* Jump over header */
+ // Jump over header
if(url_fseek(pb, MTV_HEADER_SIZE, SEEK_SET) != MTV_HEADER_SIZE)
- return AVERROR_IO;
+ return AVERROR(EIO);
- return(0);
+ return 0;
}
static int mtv_read_packet(AVFormatContext *s, AVPacket *pkt)
{
MTVDemuxContext *mtv = s->priv_data;
- ByteIOContext *pb = &s->pb;
+ ByteIOContext *pb = s->pb;
int ret;
-#ifndef WORDS_BIGENDIAN
+#if !HAVE_BIGENDIAN
int i;
#endif
- ret = 0;
-
- if(mtv->audio_subsegments >= mtv->audio_packet_count)
+ if((url_ftell(pb) - s->data_offset + mtv->img_segment_size) % mtv->full_segment_size)
{
url_fskip(pb, MTV_AUDIO_PADDING_SIZE);
ret = av_get_packet(pb, pkt, MTV_ASUBCHUNK_DATA_SIZE);
if(ret != MTV_ASUBCHUNK_DATA_SIZE)
- return AVERROR_IO;
+ return AVERROR(EIO);
- mtv->audio_packet_count++;
+ pkt->pos -= MTV_AUDIO_PADDING_SIZE;
pkt->stream_index = AUDIO_SID;
}else
{
ret = av_get_packet(pb, pkt, mtv->img_segment_size);
if(ret != mtv->img_segment_size)
- return AVERROR_IO;
+ return AVERROR(EIO);
-#ifndef WORDS_BIGENDIAN
+#if !HAVE_BIGENDIAN
/* pkt->data is GGGRRRR BBBBBGGG
* and we need RRRRRGGG GGGBBBBB
for(i=0;i<mtv->img_segment_size/2;i++)
*((uint16_t *)pkt->data+i) = bswap_16(*((uint16_t *)pkt->data+i));
#endif
- mtv->audio_packet_count = 1;
pkt->stream_index = VIDEO_SID;
}
- return(ret);
+ return ret;
}
AVInputFormat mtv_demuxer = {
"MTV",
- "MTV format",
+ NULL_IF_CONFIG_SMALL("MTV format"),
sizeof(MTVDemuxContext),
mtv_probe,
mtv_read_header,