Convert mp4 video file with audio of pcm_alaw, 8000Hz, mono, s16, 64 kb/s to good mp4

Questions that occur when trying to compile FFmpeg.
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vali
Posts: 2
Joined: Thu Jun 27, 2019 8:31 am

Convert mp4 video file with audio of pcm_alaw, 8000Hz, mono, s16, 64 kb/s to good mp4

Post by vali » Thu Jun 27, 2019 8:45 am

Hello people,
I having a trouble to play this video file on my VLC/Windows Media player and more..
I want to convert this file to a playable file and then play it in my website.
When I run this command ''ffprobe my_file.mp4" I am getting this information:

[h264 @ 000001caf5a860c0] decode_slice_header error
[h264 @ 000001caf5a860c0] no frame!
[h264 @ 000001caf5a860c0] non-existing PPS 0 referenced
Last message repeated 1 times
[h264 @ 000001caf5a860c0] decode_slice_header error
[h264 @ 000001caf5a860c0] no frame!
Input #0, mpeg, from '150_2.mp4':
Duration: 00:50:51.75, start: 13182.386222, bitrate: 983 kb/s
Stream #0:0[0x1e0]: Video: h264 (High), yuv420p(progressive), 1280x720, 25 fps, 25 tbr, 90k tbn, 50 tbc
Stream #0:1[0x1c0]: Audio: pcm_alaw, 8000 Hz, mono, s16, 64 kb/s

Thank you.

navilor
Posts: 51
Joined: Thu May 12, 2011 5:19 pm

Re: Convert mp4 video file with audio of pcm_alaw, 8000Hz, mono, s16, 64 kb/s to good mp4

Post by navilor » Thu Jul 04, 2019 7:15 pm

The video does not start on a keyframe. This is not uncommon when converting random content. It is likely that the person who created that video used the -noaccurate_seek option to dump out the content. They could have used an accurate seek.
https://trac.ffmpeg.org/wiki/Seeking

Once of the nice things about FFmpeg is you can look up just about anything that shows up on the console. I did a quick search for "decode_slice_header error" and every response was about video not starting on a keyframe.

I have been in the streaming media industry since 2008. I wrote an article on how to use FFmpeg to create streaming media compliant content. It can be found at the link below.
https://videoblerg.wordpress.com/2017/1 ... -it-wrong/

vali
Posts: 2
Joined: Thu Jun 27, 2019 8:31 am

Re: Convert mp4 video file with audio of pcm_alaw, 8000Hz, mono, s16, 64 kb/s to good mp4

Post by vali » Mon Jul 08, 2019 1:02 pm

I started my recording from my Hikvision DVR and he produces me two mp4 files (because there is a memory limit on one file - 1 GB).
The problem is in the second file, it's missing PPS/keyframe information.

The first video, I can convert to a good mp4 video file because the first file is not missing a PPS/keyframe information, I don't know why Hikvision not adding this data to the second record file.

Also, the audio of the first video file is in pcm_maluw format.

I also find a program (Hikvision Format Converter) that can convert the second file to a good video file.
Can I add a keyframe to the second video or reencode the second file without losing information?

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