[FFmpeg-devel] decklink 24/32 bit question

Dave Rice dave at dericed.com
Tue Oct 17 22:12:02 EEST 2017

> On Oct 17, 2017, at 2:59 PM, Moritz Barsnick <barsnick at gmx.net> wrote:
> Hi Doug,
> On Tue, Oct 03, 2017 at 20:39:49 -0700, Douglas Marsh wrote:
>> After digging around in places, made the following changes:
> [...]
>> It doesn't work (the audio capture is close but wrong), but believe it 
>> is a step in the correct direction. Anybody have a clue? Saw several 
>> names in cpp,c,h files including: Ramiro Polla, Luca Barbato, Deti 
>> Fliegl, Rafaël Carré and Akamai Technologies Inc.
> Did you check out Dave Rice's recent patch (on this list)? It touches
> code in a few more places, and adds an option to select 16 vs. 32 bits.
> Please test, if you can.
> Is your subject indicating that 24 bits depth could also be supported?
> If so, Dave perhaps should expand his patch to cover that.

The decklink sdk only defines two BMDAudioSampleType values: bmdAudioSampleType16bitInteger and bmdAudioSampleType32bitInteger. I don't think there's an easy way to support a 24 bit input here. Generally in this case I've used bmdAudioSampleType32bitInteger and then encode it at pcm_s24le.
Dave Rice

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