[FFmpeg-user] The efficacy of speed up a .ts file

[Carl Eugen Hoyos]

2017-05-11 5:04 GMT+02:00 Champion <championch1805 at gmail.com>:

> 1. I use JAVA to call the ffmpeg command, and the command [3] is too slow,
>     I run my code in AWS EC2(c3.xlarge) and input a 6min30sec .mp4 video,
>     the process time about 250 sec, do I have some idea to speed up the
> process time?

Only if you show us the tested command line together with the complete,
uncut console output.

>     - I change input and output to .ts file, [3] just cost 1/6 time which
> compare to output .mp4 file,
>       but the output quality is down(although they are the same pixel rate
> 1280x720),
>       is this cause by speed up .ts file will lose I frame?

Video quality is never affected by the container format.
Transport streams and mp4 have difference video encoder
defaults though, try to specify the encoder or video format you want.

>     - I try to add "-preset ultrafast" , the process time will become about
> 40 sec, but we think this still too slow, do you have some idea to improve
> this?

While this is not FFmpeg but x264-related, the answer is probably:
Throw more CPU (or a hardware encoder) on the task.

> 2. When ffmpeg is running, the CPU rate is too high.
>     my server(4 core) just run one [3] command, the CPU rate almost
> 250-300%,
>     how can I optimize the cost?
>
>     - I try to use "-threads 1", the CPU rate down to 90-100%, but the
> process time is slower.

Yes, you can't have the cake and eat it.

The option -threads 1 optimizes both encoding and decoding with
respect to unnecessary overhead but takes of course longer in
real-time.

Carl Eugen