cleanup frame_rate code, this may also fix some large file bugs

Originally committed as revision 2924 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Michael Niedermayer 2004-03-24 19:03:20 +00:00
parent 0a90160a29
commit d957696f17
1 changed files with 12 additions and 26 deletions

View File

@ -16,6 +16,9 @@
* License along with this library; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <limits.h>
#include "avformat.h"
#include "avi.h"
@ -1168,8 +1171,8 @@ static int mov_read_stts(MOVContext *c, ByteIOContext *pb, MOV_atom_t atom)
AVStream *st = c->fc->streams[c->fc->nb_streams-1];
//MOVStreamContext *sc = (MOVStreamContext *)st->priv_data;
int entries, i;
int duration=0;
int total_sample_count=0;
int64_t duration=0;
int64_t total_sample_count=0;
print_atom("stts", atom);
@ -1205,31 +1208,16 @@ printf("track[%i].stts.entries = %i\n", c->fc->nb_streams-1, entries);
#endif
}
#define MAX(a,b) a>b?a:b
#define MIN(a,b) a>b?b:a
/*The stsd atom which contain codec type sometimes comes after the stts so we cannot check for codec_type*/
if(duration>0)
{
//Find greatest common divisor to avoid overflow using the Euclidean Algorithm...
uint32_t max=MAX(duration,total_sample_count);
uint32_t min=MIN(duration,total_sample_count);
uint32_t spare=max%min;
while(spare!=0)
{
max=min;
min=spare;
spare=max%min;
}
duration/=min;
total_sample_count/=min;
//Only support constant frame rate. But lets calculate the average. Needed by .mp4-files created with nec e606 3g phone.
//To get better precision, we use the duration as frame_rate_base
st->codec.frame_rate_base=duration;
st->codec.frame_rate = c->streams[c->total_streams]->time_scale * total_sample_count;
av_reduce(
&st->codec.frame_rate,
&st->codec.frame_rate_base,
c->streams[c->total_streams]->time_scale * total_sample_count,
duration,
INT_MAX
);
#ifdef DEBUG
printf("FRAME RATE average (video or audio)= %f (tot sample count= %i ,tot dur= %i timescale=%d)\n", (float)st->codec.frame_rate/st->codec.frame_rate_base,total_sample_count,duration,c->streams[c->total_streams]->time_scale);
@ -1240,8 +1228,6 @@ printf("track[%i].stts.entries = %i\n", c->fc->nb_streams-1, entries);
st->codec.frame_rate_base = 1;
st->codec.frame_rate = c->streams[c->total_streams]->time_scale;
}
#undef MAX
#undef MIN
return 0;
}