[Libav-user] API Settings

[Carl Eugen Hoyos]

2018-01-19 17:31 GMT+01:00 Allan Rosner <arosner at alsysinc.biz>:
> My company's media server provider has reported that our buffering
> issues are related to inconsistent chunk sizes, video frame rates,
> audio frame rates and number of key frames.
>
> The media server support group sent a suggested ffmpeg command
> line that could establish constant chunk sizes, video frame rates,
> audio frame rates and number of key frames.
>
> The suggested command line is:
>
> ffmpeg -i [input-source -pix_fmt yuv420p

> -deinterlace

This option is deprecated and you should not use it.

> -vf "scale=640:360" -vsync 1 -vcodec libx264

Why are you specifying "-vsync 1"?

> -r 29.970

I don't think this is a valid framerate.

> -threads 0 -b:v: 1024k -bufsize 1216k
> -maxrate 1280k -preset medium -profile:v main -tune film -g 60
> -x264opts no-scenecut -acodec aac -b:a 192k -ac 2 -ar 48000
> -af "aresample=async=1:min_hard_comp=0.100000:first_pts=0"
> -f flv "rtmp://192.168.1.2:1935/live/myStream
> flashver=FMLE/3.0\20(compatible;\20FMSc/1.0) live=true pubUser=username
> pubPasswd=password"
>
> Two questions:
>
> 1) Do you agree that the above mentioned command line would
> produce the constant parameters mentioned above?

Since you did not provide the requested parameters, I don't think
anybody can answer this.

> 2) It appears as though all command line options are executed
> using the av_dict_set or av_opt_set API functions. Is there a
> document that states how to set the equivalent command line
> options using the API?

Several of the examples do this, grep for "av_dict_set" in doc/examples.

Carl Eugen