Blackmagic Forum

Hello, this is my chain:

PC A with CasparCG and Decklink Mini Monitor -> Intensity Pro in PC B.
Connection between PC A Decklink Mini Monitor and PC B Intensity Pro card is made via HDMI of course.

On PC B I can run VLC and get video preview from Intensity Pro via DirectShow. The problem is that I have only video, no sound. Here are VLC settings and codec informations:




As you can see VLC setect stream 1 which is audio stream, but no sound anyway.

Here is also log from ffprobe:

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Input #0, dshow, from 'video=Blackmagic WDM Capture':
  Duration: N/A, start: 0.010073, bitrate: N/A
    Stream #0:0: Video: rawvideo (HDYC / 0x43594448), uyvy422(tv), 1280x720, 50
tbr, 10000k tbn, 50 tbc


As you can see there is no audio stream detected.


Can someone help me with that problem?

EDIT:
I tried Media Express and still get only video in preview window. But bars from audio are visible, but still not getting sound. Screenshot:

Well it is normal in Media Express to see audio bars moving but to not hear the audio - as the audio is actually pushed out of the Intensity Pro's HDMI out port to an attached monitor (if you put one there - I bet you will hear the audio).

HOWEVER - that should not alter the ability for other capture utilities (like VLC) to get the audio.

Just one check... please record a short bit of the video using Media Express and check to see if the audio ends up being embedded in the recorded file.

I'm not sure where to go after this - but at least that will show "the basics" are working.

Hi, I probably know reason I dont have sound in VLC or ffmpeg. You can read about it here: http://stackoverflow.com/questions/1661 ... and-ffmpeg.

Problem is that Intensity Pro is detected by OS as a Video Capture Device "only". When you list all of your dshow devices in ffmpeg (or VLC) you can see 2 positions like (like at my screenshot from VLC): Directshow video devices and Directshow audio devices. Intensity Pro is detected only as a video device not like Decklink Mini Monitor as video device and audio device. So it is impossible to choose dshow audio source in those programs. I am mad that I boughr Intensity Pro and can not use it now because of this. Probably Mini Recorder will be good choose for me.

And yes, I can record a file in media express and that file will have a sound.

Can i ask why you need to use VLC specifically?

Damian wrote:Here is also log from ffprobe:

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Input #0, dshow, from 'video=Blackmagic WDM Capture':
  Duration: N/A, start: 0.010073, bitrate: N/A
    Stream #0:0: Video: rawvideo (HDYC / 0x43594448), uyvy422(tv), 1280x720, 50
tbr, 10000k tbn, 50 tbc


As you can see there is no audio stream detected.

I notice that is picking up the WDM driver. What about the Directshow drivers?

On my system this is what ffmpeg shows as available video/audio devices.

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ffmpeg -list_devices true -f dshow -i dummy
[dshow @ 0000000002686960] DirectShow video devices
[dshow @ 0000000002686960]  "Blackmagic WDM Capture"
[dshow @ 0000000002686960]  "Decklink Video Capture"
[dshow @ 0000000002686960]  "Decklink Video Capture (2)"
[dshow @ 0000000002686960] DirectShow audio devices
[dshow @ 0000000002686960]  "Microphone (USB Audio CODEC )"
[dshow @ 0000000002686960]  "Decklink Audio Capture (2)"
[dshow @ 0000000002686960]  "Decklink Audio Capture"
[dshow @ 0000000002686960]  "Microphone (2- Wirecast Virtual"
[dshow @ 0000000002686960]  "Microphone (Wirecast Virtual Mi"
[dshow @ 0000000002686960]  "Stereo Mix (Realtek High Defini"


I'm not entirely sure why I have two Directshow devices showing up. It may be because I also have an ATEM 1/ME and I connect that via USB3 (it is not connected currently). Anyhow... my Intensity Pro works great with all the capture apps I use (although I do not in fact use ffmpeg)

Sam Jones wrote:Can i ask why you need to use VLC specifically?

VLC is only for fast preview, what I really need is ffmpeg.

Liam Kennedy wrote:I notice that is picking up the WDM driver. What about the Directshow drivers?

What do you mean? Intensity Pro card is detected ONLY as Blackmagic WDM Capture device in Directshow Video Devices.

Ow, I understand you now: here is command line for ffprobe which I used to create that log from ffprobe:

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ffprobe -f dshow -i video="Blackmagic WDM Capture"

As you can see I can specify which device I want to use here as video input. I also can make something like this:

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ffprobe -f dshow -i video="Blackmagic WDM Capture":audio="AUDIO-DEVICE-NAME"

But with Intensity Pro I dont have direct show audio device...

Liam Kennedy wrote:Anyhow... my Intensity Pro works great with all the capture apps I use (although I do not in fact use ffmpeg)

Can you try preview in VLC? Do you have sound from Intensity Pro in VLC?

Well try the command line I show in my post above. That lists all the devices available and you should see there are two other decklink devices. The WDM driver is distinct from the decklink device. Try using the listed decklink devices instead

Ok, I made a fresh install of my video card drivers, here is list of my DirectShow Devices:

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[dshow @ 00000000043e7720] DirectShow video devices
[dshow @ 00000000043e7720]  "Blackmagic WDM Capture"
[dshow @ 00000000043e7720]  "Decklink Video Capture"
[dshow @ 00000000043e7720] DirectShow audio devices
[dshow @ 00000000043e7720]  "Decklink Audio Capture"


Unfortunatly I have video preview only on Blackmagic WDM Capture device. When I choose Decklink Video Capture I have black screen. When as audio I choose Decklink Audio Capture I still dont have audio .

Here are stream parameters when Decklink Video Capture is choosen:

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Stream 0:
   Type: Video
   Codec: Packed YUV 4:2:2, U:Y:V:Y (UYVY)
   Resolution: 1280x720
   Frame rate: 60.000240 <- WEIRD, cause it should be 50, cause I set video mode for my video card to be 720p 50.


Here is screenshot with BlackMagic settings:




I will also paste logs from ffprobe:

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ffprobe -f dshow -i video="Decklink Video Capture":audio="Decklink Audio Capture"
Input #0, dshow, from 'video=Decklink Video Capture:audio=Decklink Audio Capture
':
  Duration: N/A, start: 0.039713, bitrate: 1536 kb/s
    Stream #0:0: Video: rawvideo (UYVY / 0x59565955), uyvy422, 720x486, 29.97 tb
r, 10000k tbn, 29.97 tbc
    Stream #0:1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s


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ffprobe -f dshow -i video="Blackmagic WDM Capture":audio="Decklink Audio Capture"

Input #0, dshow, from 'video=Blackmagic WDM Capture:audio=Decklink Audio Capture
':
  Duration: N/A, start: 0.241295, bitrate: N/A
    Stream #0:0: Video: rawvideo (HDYC / 0x43594448), uyvy422(tv), 1280x720, 50
fps, 50 tbr, 10000k tbn, 50 tbc
    Stream #0:1: Audio: pcm_s16le, 48000 Hz, 2 channels, s16, 1536 kb/s


EDIT
Ok, problem solved. Here is ffplay command which allow you to preview Intensity Pro output with sound (maybe someone else will have that problem too):

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ffplay -f dshow -video_size 1280x720 -framerate 50 -i video="Decklink Video Capture":audio="Decklink Audio Capture" ^