[Libav-user] help needed on "Encoding .png images with h264 to a file on disk"

[laddoe]

Hi Gonzalo, all,

thanks for pointing out what I did wrong. I now get files that are of reasonable sizes 20 MB, something that one would expect. I have added the .h and .cpp file that I have modified according to your feedback and I have also added the .h file for the image class. But the generated videofiles that I get can not be read by VLC or any other application.
When I run "ffmpeg.exe -v error -i c:\tmp\myVideo.mp4 -f null - >error.log 2>&1 " , I get the following error lines multiple times :

[h264 @ 05c0c780] No start code is found.
[h264 @ 05c0c780] Error splitting the input into NAL units.
Error while decoding stream #0:0: Invalid data found when processing input

I have also attached a debug output file that is created by my C++/Qt application in which you'll see which images are send to the encoder. What I don't understand is that the first 26 frames are send to the encoder but not written to the file, I know that the H264 needs some frames before it starts encoding but I would like those frames to be written to the videofile as well.

Your help is greatly appreciated.
________________________________
Van: Libav-user <libav-user-bounces at ffmpeg.org> namens Gonzalo Garramuño <ggarra13 at gmail.com>
Verzonden: maandag 22 februari 2021 17:55
Aan: libav-user at ffmpeg.org <libav-user at ffmpeg.org>
Onderwerp: Re: [Libav-user] help needed on "Encoding .png images with h264 to a file on disk"



El 22/2/21 a las 05:25, laddoe escribió:
can anybody please help me with my post of 2 days ago, I'm really stuck but not able to understand what is wrong. I have also tried several different code examples but it all ends up the same as mentioned in the post. Am I not understanding this ? Are my expectations of the results incorrect? I'm new to this so please bear with me.



One thing that is wrong in your code is that you never call av_write_trailer(), which should be called before avio_close().

Also, there's no need for m_file in your code.  avformat handles the file for you.

Other things are hard to say, as you don't provide the code to the Image or cv::Mat classes.  You should provide a self-compilable example for us to help you.
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