X-Git-Url: https://git.sesse.net/?a=blobdiff_plain;f=bmusb.cpp;h=83ea717dd678512c6addbaf7609affd594115116;hb=e287f28087aef9cfd6aa47acd0d283bc177a9d70;hp=088fc9853f5d6a3df87ab00ac44971b768200f64;hpb=01ddb8f836114c07cff3ca040d9ed2c946b2fdbf;p=bmusb

diff --git a/bmusb.cpp b/bmusb.cpp
index 088fc98..83ea717 100644
--- a/bmusb.cpp
+++ b/bmusb.cpp
@@ -1,4 +1,4 @@
-// Intensity Shuttle USB3 capture driver, v0.5.4
+// Intensity Shuttle USB3 capture driver, v0.7.1
 // Can download 8-bit and 10-bit UYVY/v210-ish frames from HDMI, quite stable
 // (can do captures for hours at a time with no drops), except during startup
 // 576p60/720p60/1080i60 works, 1080p60 does not work (firmware limitation)
@@ -199,6 +199,7 @@ bool decode_video_format(uint16_t video_format, VideoFormat *decoded_video_forma
 	constexpr VideoFormatEntry entries[] = {
 		{ 0x01f1,  720,  480,   0, 40,  5, 60000, 1001, false },  // 480p59.94 (believed).
 		{ 0x0131,  720,  576,   0, 44,  5,    50,    1, false },  // 576p50.
+		{ 0x0151,  720,  576,   0, 44,  5,    50,    1, false },  // 576p50.
 		{ 0x0011,  720,  576,   0, 44,  5,    50,    1, false },  // 576p50 (5:4).
 		{ 0x0143, 1280,  720,   0, 25,  5,    50,    1, false },  // 720p50.
 		{ 0x0103, 1280,  720,   0, 25,  5,    60,    1, false },  // 720p60.
@@ -241,6 +242,26 @@ bool decode_video_format(uint16_t video_format, VideoFormat *decoded_video_forma
 	return false;
 }
 
+// There are seemingly no direct indicators of sample rate; you just get
+// one frame's worth and have to guess from that.
+int guess_sample_rate(const VideoFormat &video_format, size_t len, int default_rate)
+{
+	size_t num_samples = len / 3 / 8;
+	size_t num_samples_per_second = num_samples * video_format.frame_rate_nom / video_format.frame_rate_den;
+
+	// See if we match or are very close to any of the mandatory HDMI sample rates.
+	const int candidate_sample_rates[] = { 32000, 44100, 48000 };
+	for (int rate : candidate_sample_rates) {
+		if (abs(int(num_samples_per_second) - rate) < 50) {
+			return rate;
+		}
+	}
+
+	fprintf(stderr, "%ld samples at %d/%d fps (%ld Hz) matches no known sample rate, keeping capture at %d Hz\n",
+		num_samples, video_format.frame_rate_nom, video_format.frame_rate_den, num_samples_per_second, default_rate);
+	return default_rate;
+}
+
 }  // namespace
 
 FrameAllocator::~FrameAllocator() {}
@@ -332,6 +353,7 @@ void BMUSBCapture::dequeue_thread_func()
 	if (has_dequeue_callbacks) {
 		dequeue_init_callback();
 	}
+	size_t last_sample_rate = 48000;
 	while (!dequeue_thread_should_quit) {
 		unique_lock<mutex> lock(queue_lock);
 		queues_not_empty.wait(lock, [this]{ return dequeue_thread_should_quit || (!pending_video_frames.empty() && !pending_audio_frames.empty()); });
@@ -343,6 +365,7 @@ void BMUSBCapture::dequeue_thread_func()
 		AudioFormat audio_format;
 		audio_format.bits_per_sample = 24;
 		audio_format.num_channels = 8;
+		audio_format.sample_rate = last_sample_rate;
 		if (uint16_less_than_with_wraparound(video_timecode, audio_timecode)) {
 			printf("Video block 0x%04x without corresponding audio block, dropping.\n",
 				video_timecode);
@@ -383,10 +406,16 @@ void BMUSBCapture::dequeue_thread_func()
 			VideoFormat video_format;
 			audio_format.id = audio_frame.format;
 			if (decode_video_format(video_frame.format, &video_format)) {
+				if (audio_frame.frame.len != 0) {
+					audio_format.sample_rate = guess_sample_rate(video_format, audio_frame.frame.len, last_sample_rate);
+					last_sample_rate = audio_format.sample_rate;
+				}
 				frame_callback(video_timecode,
 					       video_frame.frame, HEADER_SIZE, video_format,
 					       audio_frame.frame, AUDIO_HEADER_SIZE, audio_format);
 			} else {
+				video_frame_allocator->release_frame(video_frame.frame);
+				audio_format.sample_rate = last_sample_rate;
 				frame_callback(video_timecode,
 				               FrameAllocator::Frame(), 0, video_format,
 					       audio_frame.frame, AUDIO_HEADER_SIZE, audio_format);
@@ -453,8 +482,8 @@ void BMUSBCapture::start_new_audio_block(const uint8_t *start)
 		//dump_audio_block();
 		queue_frame(format, timecode, current_audio_frame, &pending_audio_frames);
 	}
-	//printf("Found audio block start, format 0x%04x timecode 0x%04x, previous block length was %d\n",
-	//	format, timecode, read_current_audio_block);
+	//printf("Found audio block start, format 0x%04x timecode 0x%04x\n",
+	//	format, timecode);
 	current_audio_frame = audio_frame_allocator->alloc_frame();
 }