Fast forward encoded H264

[Joseph_W_2]

Hello fellows,

I am not sure what is the correct file extension of the encoded output file I should set.
If I set '.h264', it will play only on VLC while setting it to '.mp4' it will play only on Windows Media Player.
In both cases, fast forwarding the video is problematic.
The Media Player won't let me FF while in the VLC I can FF, but the pictures become blocky and smeared.
My program is the 'sample_encode' that comes with the SDK, with no changes in the default parameters.
I use the SW encoder since I haven't got yet a platform with a Intel GPU.

Many thanks,

Joseph

[Alexey_F_Intel]

independently how you name an output stream sample_encode will produce elementary NAL units sequence. sample do not wrap witha any container. so fast forwarding player's capability is limited by seeking an IDR frame. 

To your question - formally *.h264 would be more appropriate. *.mp4 denotes your video stream wrapped with corresponding container but it is not.  

[Joseph_W_2]

Hello Alexey, Thanks a lot for the reply. Does this explain why the video becomes blocky and smeared? I thought that after finding an IDR frame, the video should be played smootly, or am I wrong? Many thanks, Joseph

[Alexey_F_Intel]

you right, after finding IDR playback should be smooth. but if your video stream has got only 1 IDR then player has an option to stop at the end or jump to P frames ignoring missed reference frames - in this case you observe blocky corrupted picture.

you can drop me your clip - I will give the exact answer

[Joseph_W_2]

Hello Alexey,

Thanks for the reply.

Unfortunately I don't have direct access to the internet so uploading the clip will be quite cumbersome.

I would much appreciate if I can send the clip to your email if possible.

If my video has only one IDR where what are the parameters I should set in order to create a video with

multiple IDRs? Sorry if the question seems simple, I am a begginer in the field of video compression...

Joseph 

[Alexey_F_Intel]

to get up to speed quickly you need better tool chain. check this https://software.intel.com/en-us/intel-video-pro-analyzer

Video Pro Analyzer and Video Quality Caliper will give your most video related questions answered.

I double checked with sample_encode - it has defaut setting to insert I frame every 256th frame, and every I makes as IDR. Another guess with your blocky video - you did not set target bitrate. in this case sample uses some default value which can be too small for your content and the result completelly blocky video

Thanks, Alexey