Native Development

[smcveigh]

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nirhor_roy wrote:

@smcveigh Actually I am trying to make an application that does video call. So with current camera_api is it possible to create a video call application? The default bandwidth requirement is just too high.

Is there some way in which I can only record video and not audio? If the recorder is not started by the video recorder, I can start my own recorder and that solves the  problem.

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The functionality you are asking for is not yet available.  It will be available in a future release -- I am still formalizing the interface.

That being said.. if you want to try doing a software video encoder using some freely available video codec, you could look into porting one to the platform and feeding it with the viewfinder frames.

Cheers,

Sean

[smcveigh]

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nirhor_roy wrote:

Just to find out this what I can find from the uncompressed video frame? Does it contain audio as well? If it does how can I separate the audio from video? Please help!!

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The uncompressed video frame is video only.  If you need audio, you will have to open the microphone and read the pcm audio data yourself.

Cheers,

Sean

[nirhor_roy]

Is video recording possible while microphone is open?I do not think so. How can I get the uncompressed video frame when the microphone is open then?

[smcveigh · Accepted solution]

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nirhor_roy wrote:

Is video recording possible while microphone is open?I do not think so. How can I get the uncompressed video frame when the microphone is open then?

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The camera_start_video() call, which is opening the microphone, is unnecessary in this case.

You can just register a viewfinder callback when starting the viewfinder.

something like:

void vf_callback(camera_handle_t handle,
                 camera_buffer_t* buf,
                 void* arg)
{
    if (buf->frametype == CAMERA_FRAMETYPE_NV12) {
        printf("got video buffer of size %d x %d\n",
               buf->framedesc.nv12.width,
               buf->framedesc.nv12.height);
    }
}

camera_start_video_viewfinder(handle, vf_callback, NULL, NULL);

You should only use camera_start_video() if you want to record a file to disk using the built-in MP4 encoder.

Cheers,

Sean

[nirhor_roy]

Is it possible to get any other type of frames? the rgb frames would be needed for encoding by codecs like h264. So let me know if there is any configuring option for getting rgb frames?

[smcveigh]

There will be support for RGB frames soon.

H.264 encodes the YUV colour space which is presented by NV12 though, so I don't know why you think you need RGB.

Cheers,

Sean

[Innovatology]

Sean, can we...

1. disable or configure Auto Gain Control prior to starting the recording, 
2. get access to raw PCM while recording,
3. adjust gain while recording?

While AGC is nice for simple point-and-shoot, it needs tweaking for more sophisticated applications.

[smcveigh]

We have no manual AGC setting yet.  However, auto-exposure can be locked at any time.

Regarding access to PCM audio -- not yet.  The video recording graph is not yet configurable, so you are stuck with "video + microphone" for the time being.  This will be changing before BB10 launch and I'm hoping to get it out in a beta between now and then.

Cheers,

Sean

[Innovatology]

Of course I mean optional manual audio gain, and access to sample data to be able to indicate levels and clipping. An API for that would be very usefull, and would differentiate BB10 from other platforms.

[smcveigh]

Ah, so to clarify, you aren't asking about video AGC?

I can't really comment on the audio APIs as I'm not as familiar.

Can you outline a specific use case you have in mind so that I understand exactly what you're asking for?  I think you're asking about doing a level monitor for the mic while recording video.

Cheers,

Sean