[FFmpeg-devel] [PATCH 1/1] avdevice/decklink_dec: Autodetect the video input format

[Marton Balint]

On Mon, 20 Nov 2017, Jeyapal, Karthick wrote:

>> On 11/20/17, 12:39 AM, "Marton Balint" <cus at passwd.hu> wrote:
>
>> Thanks, there is one more thing I still don't get:
>
> [...]
>>> +    // 1 second timeout
>>> +    for (i = 0; i < 10; i++) {
>>> +        av_usleep(100000);
>>> +        // Sometimes VideoInputFrameArrived is called before VideoInputFormatChanged
>>> +        // So don't break for bmd_mode == AUTODETECT_DEFAULT_MODE
>
>> Even if you get a frame for the default mode, and
>> VideoInputFrameArrived is called early, the bmdFrameHasNoInputSource
>> flag should be set, so ctx->bmd_mode remains unknown, therefore you don't
>> have to handle it specially.
>>
>> Are you saying that the Decklink drivers are buggy, and there are cases
>> where you get a frame without the bmdFrameHasNoInputSource flag, and then
>> a VideoInputFormatChanged callback later?
>
> Yes, there are cases where you get a frame without the bmdFrameHasNoInputSource
> flag, and then a VideoInputFormatChanged called later. And it is random.
> But I don’t know if it could be called as a driver bug, since the getWidth and getHeight would return the correct values.
> During my testing, I observed a 1080p30 would randomly get detected as,
> AUTODETECT_DEFAULT_MODE because of VideoInputFrameArrived called early.
> Hence I added that extra condition to handle it specially.

Ok, applied the series with some minor whitespace/comment fixes.

Thanks,
Marton