[FFmpeg-user] ffmpeg audio distortion using blackmagic

Micael Silva micaelsilva at gmail.com
Wed Jul 18 20:53:04 EEST 2018


On Wed, Jul 18, 2018 at 1:11 PM, Flumotion Support <support at flumotion.com>
wrote:

> Hello everybody
>
> I have problems capturing a sdi flow with ffmpeg, I'm using a blackmagic
> mini recorder pro, after a while of working the capture the audio is
> distorted and the only way to fix it is to restart ffmpeg.
>
> this is my pipeline
> /usr/local/bin/ffmpeg -re -loglevel 48 -format_code pal -f decklink -i
> DeckLink Mini Recorder -audio_input embedded -video_input sdi -vcodec
> libx264 -crf 22 -preset:v veryfast -b:v 900k -pix_fmt yuv420p -acodec
> libfdk_aac -ab 64k -ar 48000 -ac 2 -s 640x360 -f flv rtmp://
> myserver.com:1935/test/live
>
> I add an audio capture that is distorted from the second 10.
> I will grow any help you can offer me.
>
> Thanks in advance
> King regards
>
> ‚Äč
>  croppedvideo.mp4
> <https://drive.google.com/a/flumotion.com/file/d/1R_
> pjUps2xkLYepeTxLIWKxqSy_qCnTF0/view?usp=drive_web>
>

The DeckLink Mini it's kinda of problematic with audio because it's very
restrictive about sample rate, only inputs and outputs 48KHz, and it shows
up in strange ways along the pipeline. Did you tried the same thing using
the HDMI input? Or recording to a MP4 file, without the -re param?


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