[FFmpeg-devel] [PATCH] libavdevice/decklink: 32 bit audio support

Douglas Marsh ffmpeg at dx9s.net
Fri Oct 20 18:06:23 EEST 2017


On 2017-10-19 20:08, Douglas Marsh wrote:
> On 2017-10-18 12:23, Dave Rice wrote:
>> [...]
>> Updated.
>> 
>> From 1e5ff78fec9b13eccac9a96acc358bbfd6a7015d Mon Sep 17 00:00:00 2001
>> From: Dave Rice <dave at dericed.com>
>> Date: Wed, 18 Oct 2017 15:21:46 -0400
>> Subject: [PATCH] libavdevice/decklink: 32 bit audio support
>> 

I (quickly before going to bed) did the following from commit: 
858db4b01fa2b55ee55056c033054ca54ac9b0fd

(documented the morning after, but believe this is correct)

Works:
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' -c:a 
pcm_s24le -vcodec libx264 -crf 0 -preset superfast test.mov
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' -c:a 
pcm_s32le -vcodec libx264 -crf 0 -preset superfast test.mkv
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' 
-acodec flac -vcodec libx264 -crf 0 -preset superfast test.mkv

Doesn't work (issues with MOV and 32-bit audio so assuming not a deal, 
unless 32-bit audio SHOULD work)
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' 
-acodec copy -vcodec libx264 -crf 0 -preset superfast test.mov
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' -c:a 
pcm_s32le -vcodec libx264 -crf 0 -preset superfast test.mov

Haven't tested rgb10 (assuming is "soft" fails [600.0fps*] or complains 
like in previous builds):
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format rgb10 -i 'DeckLink Studio 4K' -c:a 
copy -vcodec libx264 -crf 0 -preset superfast test.mkv

*=soft fails as in older builds getting a reported 600.0fps (I posted 
something here previous) when -c copy output.avi and analyze the avi 
file metadata

(side note)
Also works: (with v4l2loopback)
$ ffmpeg10 -format_code Hp59 -f decklink -video_input hdmi -audio_input 
embedded -audio_depth 32 -raw_format argb -i 'DeckLink Studio 4K' -c:a 
null -c:v rawvideo -pix_fmt yuv420p -threads 2 -f v4l2 /dev/videoX

(where ffmpeg10 = 
LD_PRELOAD=/usr/lib/x86_64-linux-gnu/x264-10bit/libx264.so.148 ffmpeg 
"$@")

--Doug (dx9s)


More information about the ffmpeg-devel mailing list