When I try to open a movie I just created with the command:
ffmpeg -pattern_type glob -i '*.JPG' -s 640x480 movie.mp4
I get an error from QuickTime:
The document “movie.mp4” could not be opened.
The file may be damaged or may not be a movie file that is compatible with QuickTime Player.
I used the same command on a set of images generated from an iSight time lapse, but in this case the above images are from a digital camera. The resolution is a lot higher, but I am scaling it to 640x480 and I don't see anything in the output that suggests a problem:
Input #0, image2, from '*.JPG':
Duration: 00:00:04.76, start: 0.000000, bitrate: N/A
Stream #0:0: Video: mjpeg, yuvj422p(pc), 4928x3264, 25 tbr, 25 tbn, 25 tbc
vs. the working movie:
Input #0, image2, from '*.JPG':
Duration: 00:01:23.72, start: 0.000000, bitrate: N/A
Stream #0:0: Video: mjpeg, yuvj420p(pc), 640x480 [SAR 1:1 DAR 4:3], 25 fps, 25 tbr, 25 tbn, 25 tbc
And for the output:
Output #0, mp4, to 'movie.mp4':
Metadata:
encoder : Lavf55.19.104
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuvj422p, 640x480, q=-1--1, 12800 tbn, 25 tbc
Stream mapping:
Stream #0:0 -> #0:0 (mjpeg -> libx264)
vs. for the working one:
Output #0, mp4, to 'movie.mp4':
Metadata:
encoder : Lavf55.19.104
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuvj420p, 640x480 [SAR 1:1 DAR 4:3], q=-1--1, 12800 tbn, 25 tbc
Stream mapping:
Stream #0:0 -> #0:0 (mjpeg -> libx264)
Aside from the working movie being longer and a lower source resolution, the only difference I can see is that there is an extra "[SAR 1:1 DAR 4:3]" mentioned in the video stream, but I have no idea what this is, or how to try to force it in the non-working movie.
Update: I just downloaded VLC and it plays the movie fine. So I know ffmpeg isn't at fault here.
ffprobe video.mp4
can be used to check which pixel format is used.