public H264(VideoDevice device)
{
this.device = device;
// Pi4 only supports two:
// "H.264", H264
// "Motion-JPEG", MJPEG
sImageFormatDescription formatDesc = device.enumerateFormats(inputBufferType)
.first(i => i.pixelFormat == inputPixelFormat, "h.264 decoder requires a hardware capable of decoding h.264. The provided video device can’t do that.");
// Logger.logVerbose( "Compressed format: {0}", formatDesc );
inputFormat = new sImageFormat(ref formatDesc);
// We gonna be using NV12, but generally speaking Pi4 supports following:
// "Planar YUV 4:2:0", YUV420
// "Planar YVU 4:2:0", YVU420
// "Y/CbCr 4:2:0", NV12
// "Y/CrCb 4:2:0", NV21
// "16-bit RGB 5-6-5", RGB565
formatDesc = device.enumerateFormats(outputBufferType)
.first(i => i.pixelFormat == outputPixelFormat, "h.264 decoder requires a hardware capable of decoding h.264 into NV12. The provided video device can’t do that.");
outputFormat = new sImageFormat(ref formatDesc);
inputSize = SizeSupported.query(device, inputPixelFormat);
outputSize = SizeSupported.query(device, outputPixelFormat);
}
internal sImageFormat(ref sImageFormatDescription src)
{
bufferType = src.type;
index = src.index;
description = src.description;
pixelFormat = src.pixelFormat;
flags = src.flags;
}
// Called on decoder thread
void iDecoderEvents.onDynamicResolutionChange()
{
sSelection selection = default;
selection.type = eBufferType.VideoCaptureMPlane;
selection.target = eSelectionTarget.Compose;
device.file.call(eControlCode.G_SELECTION, ref selection);
// Logger.logInfo( "selection: {0}", selection ); // Appears to be correct, i.e. matches what's in the PPS of the video
if (selection.rect != decodedSize.cropRect)
{
throw new ApplicationException($"Linux failed to decode SPS from the video; SPS says the crop rectangle is { decodedSize.cropRect }, Linux decoded as { selection.rect }");
}
sStreamDataFormat sdf = new sStreamDataFormat {
bufferType = eBufferType.VideoCaptureMPlane
};
device.file.call(eControlCode.G_FMT, ref sdf);
Logger.logVerbose("Automatically selected format: {0}", sdf);
decodedPixelFormat = sdf.pix_mp;
colorFormat = sdf.pix_mp.colorFormat();
Logger.logInfo("Dynamic resolution change: {0}", colorFormat);
return;
// The following code causes endless loop of resolution changes, despite nothing being changed, really
// state = eDecoderState.DrainRezChange;
// The setup workflow in that V4L spec is BS, unfortunately :-(
device.stopStreaming(eBufferType.VideoCaptureMPlane);
int decodedBuffersCount = decoded.buffersCount;
decoded.Dispose();
decoded = null;
sImageFormatDescription format = device.findOutputFormat();
Logger.logVerbose("Picked the format \"{0}\", {1}, flags {2}", format.description, format.pixelFormat, format.flags);
// Destroy the old decoded buffers
sRequestBuffers rbDecoded = new sRequestBuffers()
{
type = eBufferType.VideoCaptureMPlane,
memory = eMemory.MemoryMap
};
device.file.call(eControlCode.REQBUFS, ref rbDecoded);
// Fix a few things there
sdf.pix_mp.pixelFormat = ePixelFormat.NV12; // This one is actually pre-selected, prolly because of the initial one we set in the captureSetup method
sdf.pix_mp.quantization = eQuantization.FullRange; // Linux defaults to limited range, not what we want.
device.file.call(eControlCode.S_FMT, ref sdf);
// Logger.logVerbose( "Set format: {0}", sdf );
// Create new set of decoded buffers, same count as before
decoded = new DecodedQueue(device, decodedBuffersCount);
// Finally, resume the video
device.startStreaming(eBufferType.VideoCaptureMPlane);
decoded.enqueueAll();
}
