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simplify PTS handling

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Originally committed as revision 10291 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Mike Melanson 2007-09-04 17:33:35 +00:00
parent f55f27ba98
commit 80a16ccf82
1 changed files with 10 additions and 33 deletions
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43
libavformat/flic.c
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@ -39,16 +39,15 @@
originated in Dave's Targa Animator (DTA) */
#define FLIC_CHUNK_MAGIC_1 0xF1FA
#define FLIC_CHUNK_MAGIC_2 0xF5FA
#define FLIC_MC_PTS_INC 6000 /* pts increment for Magic Carpet game FLIs */
#define FLIC_DEFAULT_PTS_INC 6000 /* for FLIs that have 0 speed */
#define FLIC_MC_SPEED 5 /* speed for Magic Carpet game FLIs */
#define FLIC_DEFAULT_SPEED 5 /* for FLIs that have 0 speed */
#define FLIC_HEADER_SIZE 128
#define FLIC_PREAMBLE_SIZE 6
typedef struct FlicDemuxContext {
int frame_pts_inc;
int64_t pts;
int video_stream_index;
int frame_number;
} FlicDemuxContext;
static int flic_probe(AVProbeData *p)
@ -74,7 +73,7 @@ static int flic_read_header(AVFormatContext *s,
int speed;
int magic_number;
flic->pts = 0;
flic->frame_number = 0;
/* load the whole header and pull out the width and height */
if (get_buffer(pb, header, FLIC_HEADER_SIZE) != FLIC_HEADER_SIZE)
@ -82,6 +81,8 @@ static int flic_read_header(AVFormatContext *s,
magic_number = AV_RL16(&header[4]);
speed = AV_RL32(&header[0x10]);
if (speed == 0)
speed = FLIC_DEFAULT_SPEED;
/* initialize the decoder streams */
st = av_new_stream(s, 0);
@ -108,14 +109,12 @@ static int flic_read_header(AVFormatContext *s,
st->codec->extradata = av_malloc(FLIC_HEADER_SIZE);
memcpy(st->codec->extradata, header, FLIC_HEADER_SIZE);
av_set_pts_info(st, 33, 1, 90000);
/* Time to figure out the framerate: If there is a FLIC chunk magic
* number at offset 0x10, assume this is from the Bullfrog game,
* Magic Carpet. */
if (AV_RL16(&header[0x10]) == FLIC_CHUNK_MAGIC_1) {
flic->frame_pts_inc = FLIC_MC_PTS_INC;
av_set_pts_info(st, 64, FLIC_MC_SPEED, 70);
/* rewind the stream since the first chunk is at offset 12 */
url_fseek(pb, 12, SEEK_SET);
@ -127,36 +126,15 @@ static int flic_read_header(AVFormatContext *s,
memcpy(st->codec->extradata, header, 12);
} else if (magic_number == FLIC_FILE_MAGIC_1) {
/*
* in this case, the speed (n) is number of 1/70s ticks between frames:
*
* pts n * frame #
* -------- = ----------- => pts = n * (90000/70) * frame #
* 90000 70
*
* therefore, the frame pts increment = n * 1285.7
*/
flic->frame_pts_inc = speed * 1285.7;
av_set_pts_info(st, 64, speed, 70);
} else if ((magic_number == FLIC_FILE_MAGIC_2) ||
(magic_number == FLIC_FILE_MAGIC_3)) {
/*
* in this case, the speed (n) is number of milliseconds between frames:
*
* pts n * frame #
* -------- = ----------- => pts = n * 90 * frame #
* 90000 1000
*
* therefore, the frame pts increment = n * 90
*/
flic->frame_pts_inc = speed * 90;
av_set_pts_info(st, 64, speed, 1000);
} else {
av_log(s, AV_LOG_INFO, "Invalid or unsupported magic chunk in file\n");
return AVERROR_INVALIDDATA;
}
if (flic->frame_pts_inc == 0)
flic->frame_pts_inc = FLIC_DEFAULT_PTS_INC;
return 0;
}
@ -188,7 +166,7 @@ static int flic_read_packet(AVFormatContext *s,
break;
}
pkt->stream_index = flic->video_stream_index;
pkt->pts = flic->pts;
pkt->pts = flic->frame_number++;
pkt->pos = url_ftell(pb);
memcpy(pkt->data, preamble, FLIC_PREAMBLE_SIZE);
ret = get_buffer(pb, pkt->data + FLIC_PREAMBLE_SIZE,
@ -197,7 +175,6 @@ static int flic_read_packet(AVFormatContext *s,
av_free_packet(pkt);
ret = AVERROR(EIO);
}
flic->pts += flic->frame_pts_inc;
packet_read = 1;
} else {
/* not interested in this chunk */