Videoless mp4 - not the intended sitaution

[carlarogers]

.mp4 plays audio only...sux. I am hoping you can help.

Started with .mov file made with iMovie. Here is the media info



When coverting to mp4 using ffmpeg, the resulting file will not play in quicktime or in a Firefox. It does, however, play in vlc on mac.

Here is the ffmepg command used:

 ffmpeg -i stats_on_police.mov -vcodec h264 -acodec aac stats_on_police.mp4

Media info for .mp4 file


The videoless mp4 is at this link: https://legacy-systems.biz/longview2500/topics/2020_race_riots/stats_on_genocide/img/s..._on_police.mp4

[LigH.de]

Strange. You used the parameter -vcodec copy, but ffmpeg converted from ProRes to AVC anyway. Same for the audio: PCM to AAC, despite -acodec copy. I doubt you told us the correct parameters.

The reason why the video is not visible is probably that it was encoded in High Profile 4:2:2, but most media players only support a 4:2:0 AVC profile (Main or High).

[jagabo]

The video is 10 bit AVC and uses 4:2:2 chroma subsampling. Both of those can be problematic for some players.

[carlarogers]

Strange. You used the parameter -vcodec copy, but ffmpeg converted from ProRes to AVC anyway. Same for the audio: PCM to AAC, despite -acodec copy. I doubt you told us the correct parameters.

The reason why the video is not visible is probably that it was encoded in High Profile 4:2:2, but most media players only support a 4:2:0 AVC profile (Main or High).

I am sorry, I thought I corrected my post. The ffmpeg command was:

ffmpeg -i stats_on_police.mov -vcodec h264 -acodec aac stats_on_police.mp4

Are there adjustments to the ffmpeg command that will correct the problem.

I appreciate your knowledge on this subject.

[carlarogers]

The video is 10 bit AVC and uses 4:2:2 chroma subsampling. Both of those can be problematic for some players.

Can that be corrected by adjusting the ffmpeg command? btw, I put the wrong ffmeg comamnd in the OP, which I have edited to reflect the command I used, which was

ffmpeg -i stats_on_police.mov -vcodec h264 -acodec aac stats_on_police.mp4

[jagabo]

Add -vf "format=yuv420p" to your command line after the input file spec.

ffmpeg -i stats_on_police.mov -vf "format=yuv420p" -vcodec h264 -acodec aac stats_on_police.mp4

[carlarogers]

Add -vf "format=yuv420p" to your command line after the input file spec.

ffmpeg -i stats_on_police.mov -vf "format=yuv420p" -vcodec h264 -acodec aac stats_on_police.mp4

Sorry for the slow response. This solution worked perfectly.

Thank you very much.