[Libquicktime-devel] libquicktime produced files have 0 frame count

[Steven S. <sch...@gm...>]

It's been a little while since I needed to create a 4:2:2 uncompressed
Quicktime file but now when I run the program that did this task in the
past the file shows up as having 0 frames which makes many applications
unhappy.

I've finally narrowed the problem down to the 'stts' atom having a
'sample_count' value of 0.

Included  is a simple test case that produces a 10 frame Quicktime file
named testing.mov.  Compilation was done with cc -I/usr/local/include/lqt
testqt.c -lquicktime but if you've libquicktime installed elsewhere change
the -I and / or add -L.

Running the program as ./a.out results in the file

[larry:~] sms% ls -l testing.mov
-rw-r--r--  1 sms  staff  6759228 Oct 17 16:56 testing.mov

qtinfo says the file has 0 frames

qtinfo testing.mov

Type: Quicktime
  0 audio tracks.
  1 video tracks.
    704x480, depth 24
    rate 23.976025 [24000:0] constant
    length 0 frames
    compressor 2vuy.
    Native colormodel:  Undefined
    Interlace mode:     None (Progressive)
    Pixel aspect ratio: 10:11
    No timecodes available
    supported.
  0 text tracks.

and the frame rate doesn't look right either, I'd expect [24000:1001].   I
thought too that the Native colormodel should be 422.

Looking at the file using an Apple utility I se  the 'stts' atom has a 0
for the 'sampCnt' (sample_count) field.  If I change that to 10 the qtinfo
output is  correct.

The test program is based on the y4mtoqt program from mjpegtools.  Y4mtoqt
was working for years and hasn't changed, so something in libquicktime's
been broken in the last few months or
so.
I've tried attaching what I thought were small enough screenshots showing
the atoms of the broken file but a 64KB limit on mail times is causing the
mail to be held pending moderator approval.

here's the  test program that produces a file with 10 junk frames.

#include <stdio.h>

#include <stdlib.h>

#include <stdint.h>

#include <quicktime.h>

#include <lqt.h>

#include <colormodels.h>


int

main(int argc, char **argv)

{

char *outfilename = "testing.mov";

uint8_t *yuv[3];

int y_len, u_len, v_len, nfields = 1, dominance = 0;

int imodel = 0;

int err, i, c, y4mchroma;

char *qtchroma = NULL;

quicktime_t *qtf;

quicktime_pasp_t pasp;


 qtchroma = QUICKTIME_2VUY;

imodel = BC_YUV422P;    /* Input is planar */


 y_len = 704 * 480;

u_len = 352 * 480 ;

v_len = 352 * 480 ;

yuv[0] = malloc(y_len);

yuv[1] = malloc(u_len);

yuv[2] = malloc(v_len);


 qtf = quicktime_open(outfilename, 0, 1);

if (!qtf)

fprintf(stderr,"quicktime_open(%s,0,1) failed", outfilename);


 quicktime_set_video(qtf, 1,

704,

480,

(double) 24000 / 1001,

qtchroma);

lqt_set_cmodel(qtf, 0, imodel);


 dominance = 0;

nfields = 1;

lqt_set_fiel(qtf, 0, nfields, dominance);


 pasp.hSpacing = 10;

pasp.vSpacing = 11;

lqt_set_pasp(qtf, 0, &pasp);


 for (i = 0; i < 10; i++)

{

err = quicktime_encode_video(qtf, yuv, 0);

if (err != 0)

fprintf(stderr, "quicktime_encode_video failed.");

}

quicktime_close(qtf);

exit(0);

}