[FFmpeg-user] Need Help For Splitting, Re-Encoding and Joining again

Gabriel Balaich roderrooder at gmail.com
Thu Mar 29 19:57:46 EEST 2018


On Thu, Mar 29, 2018 at 10:56 AM, Gabriel Balaich <roderrooder at gmail.com>
wrote:

> Try using .ts instead of mp4, they seem to segment better, end result can
> still
> be converted back to .mp4.
>
> 1) ffmpeg -i F:\video_data_set\4k_compressed.mp4 -f segment
> -segment_time 5 -segment_start_number 1 -codec copy
> F:\video_data_set\test\%d_4k_compressed.ts
>
> 2) ffmpeg -hide_banner -i F:\video_data_set\test\1_4k_compressed.mp4
> -c:a aac -ar 44100 -b:a 128k -c:v libx264 -x264opts nal-hrd=cbr:force-cfr=1
> -pix_fmt yuv420p -profile:v baseline -level 3.0 -vf
> "scale=1280:-2,setdar=16:9" -b:v 3.9M -minrate 3.9M -maxrate 3.9M -bufsize
> 7.8M -preset ultrafast -crf 18 -r 30 -g 30 -threads 8 -copyts
> F:\video_data_set\test\1_4k_compressed_1.ts
>
> 3) ffmpeg -hide_banner -f concat -safe 0 -i
> F:\video_data_set\test\files_2.txt
> -c copy -threads 8 F:\video_data_set\4k_compressed_1.mp4
>
> On Thu, Mar 29, 2018 at 3:00 AM, Faraz Ahmed <faraz.ahmed at purelogics.net>
> wrote:
>
>>  Hi,
>>
>> We want to encode large video files faster.
>> To make encoding faster we are using multiple encoding servers.
>> Below is our process of encoding flow
>>
>>
>>    1. First we split the video into small segments using below command
>>    2. ffmpeg -i F:\video_data_set\4k_compressed.mp4 -f segment
>>    -segment_time 5 -segment_start_number 1 -codec copy -copyts
>>    -avoid_negative_ts 1 F:\video_data_set\test\%d_4k_compressed.mp4
>>    3. Then we divide these segments among multiple encoding servers
>>    4. Each encoding server re-encode the segment using below command
>>    5. ffmpeg -hide_banner -i F:\video_data_set\test\1_4k_compressed.mp4
>>    -c:a aac -ar 44100 -b:a 128k -c:v libx264 -x264opts
>> nal-hrd=cbr:force-cfr=1
>>    -pix_fmt yuv420p -profile:v baseline -level 3.0 -vf
>>    "scale=1280:-2,setdar=16:9" -b:v 3.9M -minrate 3.9M -maxrate 3.9M
>> -bufsize
>>    7.8M -preset ultrafast -crf 18 -r 30 -g 30 -threads 8
>>    F:\video_data_set\test\1_4k_compressed_1.mp4
>>    6. When all segments have re-encoded then we join them to make single
>>    file using below command
>>    7. ffmpeg -hide_banner -f concat -safe 0 -i
>> F:\video_data_set\test\files_2.txt
>>    -c copy -threads 8 F:\video_data_set\4k_compressed_1.mp4
>>
>>
>> All is performing well but the issue we are facing is that after each
>> segment there is click sound in output audio.
>> For example i have encoded 5 segments having duration 6,6,3,6 and 6
>> seconds
>> when i joined them using above mentioned command the output video has
>> click
>> sound at 6,12,15 and 21 seconds of video. I am also sharing my output
>> video
>> link below.
>>
>> https://www.dropbox.com/s/2dugqt944n19s2j/4k_compressed_1.mp4?dl=0
>>
>> Can you please help me and let me know what is the cause of this click
>> sound and how to fix and remove this click sound from output video.
>>
>>
>>
>> Thanks,
>> Faraz
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>
>
>
Didn't mean to top-post my bad, gmail is particularly annoying when trying
to avoid that.


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