lib: rework synchronization logic

On Windows it apparently happens that right after
startup of libuvc the first frames are 'out of order'.
Require at least 5 frames to be received in order
before considering the data stream synchronized.
This commit is contained in:
Steve Markgraf 2024-12-15 00:40:44 +01:00
parent a5375f79cc
commit 0ad2ea5b97

View file

@ -84,6 +84,7 @@ struct hsdaoh_dev {
uint8_t edid_seq_cnt;
int frames_since_error;
int discard_start_frames;
unsigned int in_order_cnt;
uint16_t last_frame_cnt;
uint16_t last_crc;
uint16_t idle_cnt;
@ -623,18 +624,22 @@ void hsdaoh_process_frame(hsdaoh_dev_t *dev, uint8_t *data, int size)
metadata_t meta;
hsdaoh_extract_metadata(data, &meta, dev->width);
if (le32toh(meta.magic) != 0xda7acab1)
if (le32toh(meta.magic) != 0xda7acab1) {
dev->stream_synced = false;
return;
}
/* drop duplicated frames */
if (meta.framecounter == dev->last_frame_cnt)
return;
if (dev->stream_synced) {
if (meta.framecounter != ((dev->last_frame_cnt + 1) & 0xffff))
if (meta.framecounter != ((dev->last_frame_cnt + 1) & 0xffff)) {
dev->in_order_cnt = 0;
if (dev->stream_synced)
printf("Missed at least one frame, fcnt %d, expected %d!\n",
meta.framecounter, ((dev->last_frame_cnt + 1) & 0xffff));
}
meta.framecounter, ((dev->last_frame_cnt + 1) & 0xffff));
} else
dev->in_order_cnt++;
dev->last_frame_cnt = meta.framecounter;
@ -674,7 +679,7 @@ void hsdaoh_process_frame(hsdaoh_dev_t *dev, uint8_t *data, int size)
frame_payload_bytes += payload_len*2;
}
if (dev->cb)
if (dev->cb && dev->stream_synced)
dev->cb(data, frame_payload_bytes, dev->cb_ctx);
if (frame_errors && dev->stream_synced) {
@ -683,7 +688,7 @@ void hsdaoh_process_frame(hsdaoh_dev_t *dev, uint8_t *data, int size)
} else
dev->frames_since_error++;
if (!dev->stream_synced) {
if (!dev->stream_synced && !frame_errors && (dev->in_order_cnt > 4)) {
fprintf(stderr, "Syncronized to HDMI input stream\n");
dev->stream_synced = true;
}
@ -747,7 +752,7 @@ int hsdaoh_start_stream(hsdaoh_dev_t *dev, hsdaoh_read_cb_t cb, void *ctx)
uvc_perror(res, "get_mode"); /* device doesn't provide a matching stream */
} else {
/* start the UVC stream */
dev->discard_start_frames = 60;
dev->discard_start_frames = 30;
res = uvc_start_streaming(dev->uvc_devh, &ctrl, _uvc_callback, (void *)dev, 0);
if (res < 0) {