Hi Kyle. It may be possible that the delay in acceptable grace periods is due to a difference in our input AV sources more so than the Hauppauge units themselves. I'm wondering if it would be useful to control the timeout period via a module parameter that defaults to 3 seconds perhaps? As far as the issues with concatenated output, I've just looked at the files containing a channel change and realized that VLC does show the duration as 0:00. Seeking with a keyboard isn't functional. Seeking with the timeline and a mouse is fine. Avidemux seems to have trouble editing the file. If I cut a section from a file that is from a single recording "session" it's duration is correct, sync is correct and audio properties are correct. I cannot cut across segments. MPC-HC also has duration issues with the recording. If I run the recordings through "ffmpeg -fflags +genpts -I <INPUT> -c:v copy -c:a copy <OUTPUT>", the resultant file duration is correct in VLC, I can seek with the keyboard and mouse and editing is perfect with Avidemux. But would it be better if the device just cleanly stopped recording instead of automatically resuming? Or, continuing with the module parameters idea, could we determine whether or not it will automatically restart based off a module parameter? I feel bad for not noticing the VLC issues earlier, but I mostly just use VLC to broadcast the recordings through my home network to client instances of VLC. This works well, but obviously seeking isn't relevant. ryley -----Original Message----- From: Keith Pyle [mailto:kpyle@xxxxxxxxxxxxx] Sent: Wednesday, April 09, 2014 12:28 AM To: Ryley Angus; 'Hans Verkuil'; linux-media@xxxxxxxxxxxxxxx Subject: Re: [RFC] Fix interrupted recording with Hauppauge HD-PVR On 04/07/14 22:32, Ryley Angus wrote: > Thanks Hans for getting back to me. > > I've been trying out your patch and I found the device wasn't actually > restarting the streaming/recording properly after a channel change. I > changed "msecs_to_jiffies(500))" to "msecs_to_jiffies(1000))" and had > the same issue, but "msecs_to_jiffies(2000))" > seems to be working well. I'll let it keep going for a few more hours, > but at the moment it seems to be working well. The recordings can be > ended without anything hanging, and turning off the device ends the > recording properly (mine neglected this occurrence). > > I'll let you know if I have any more issues, > > ryley > > -----Original Message----- > From: Hans Verkuil [mailto:hverkuil@xxxxxxxxx] > Sent: Tuesday, April 08, 2014 12:07 AM > To: Ryley Angus; linux-media@xxxxxxxxxxxxxxx > Subject: Re: [RFC] Fix interrupted recording with Hauppauge HD-PVR > > Hi Ryley, > > Thank you for the patch. Your analysis seems sound. The patch is > actually not bad for a first attempt, but I did it a bit differently. > > Can you test my patch? > > Regards, > > Hans > > Signed-off-by: Hans Verkuil <hans.verkuil@xxxxxxxxx> > > diff --git a/drivers/media/usb/hdpvr/hdpvr-video.c > b/drivers/media/usb/hdpvr/hdpvr-video.c > index 0500c417..a61373e 100644 > --- a/drivers/media/usb/hdpvr/hdpvr-video.c > +++ b/drivers/media/usb/hdpvr/hdpvr-video.c > @@ -454,6 +454,8 @@ static ssize_t hdpvr_read(struct file *file, char > __user *buffer, size_t count, > > if (buf->status != BUFSTAT_READY && > dev->status != STATUS_DISCONNECTED) { > + int err; > + > /* return nonblocking */ > if (file->f_flags & O_NONBLOCK) { > if (!ret) > @@ -461,11 +463,23 @@ static ssize_t hdpvr_read(struct file *file, > char __user *buffer, size_t count, > goto err; > } > > - if (wait_event_interruptible(dev->wait_data, > - buf->status == BUFSTAT_READY)) > { > - ret = -ERESTARTSYS; > + err = > wait_event_interruptible_timeout(dev->wait_data, > + buf->status == BUFSTAT_READY, > + msecs_to_jiffies(500)); > + if (err < 0) { > + ret = err; > goto err; > } > + if (!err) { > + v4l2_dbg(MSG_INFO, hdpvr_debug, > &dev->v4l2_dev, > + "timeout: restart streaming\n"); > + hdpvr_stop_streaming(dev); > + err = hdpvr_start_streaming(dev); > + if (err) { > + ret = err; > + goto err; > + } > + } > } > > if (buf->status != BUFSTAT_READY) > > > On 04/07/2014 02:04 AM, Ryley Angus wrote: >> (Sorry in advance for probably breaking a few conventions of the >> mailing lists. First time using one so please let me know what I'm >> doing wrong) >> >> I'm writing this because of an issue I had with my Hauppauge HD-PVR. >> I record from my satellite set top box using component video and >> optical audio input. I basically use "cat /dev/video0 > ~/video.ts" >> or use dd. The box is set to output audio as AC-3 over optical, but >> most channels are actually output as stereo PCM. When the channel is >> changed between a PCM channel and (typically to a movie channel) to a >> channel utilising AC-3, the HD-PVR stops the recording as the set top >> box momentarily outputs no audio. Changing between PCM channels >> doesn't cause any issues. >> >> My main problem was that when this happens, cat/dd doesn't actually >> exit. When going through the hdpvr driver source and the dmesg >> output, I found the hdpvr driver wasn't actually shutting down the >> device properly until I manually killed cat/dd. >> >> I've seen references to this issue being a hardware issue from as far >> back as 2010: >> http://forums.gbpvr.com/showthread.php?46429-HD-PVR-drops-recording-o >> n -channel-change-Hauppauge-says-too-bad >> . >> >> I tracked my issue to the file "hdpvr-video.c". Specifically, "if >> (wait_event_interruptible(dev->wait_data, buf->status = >> BUFSTAT_READY)) {" (line ~450). The device seems to get stuck waiting >> for the buffer to become ready. But as far as I can tell, when the >> channel is changed between a PCM and AC-3 broadcast the buffer status >> will never actually become ready. >> >> ... I've seen the same problem Ryley describes and handled it in user space with a cat-like program that could detect stalls and re-open the hdpvr device. This approach seems much better. Kudos to both Ryley and Hans. I concur that the 500 ms. timeout is too small. When testing my program, I tried using a variety of timeout values when I found that the HD-PVR seems to require some delay following a close before it is ready to respond. In my tests, anything of 2.5 seconds or less was not reliable. I only reached 100% re-open reliability with a 3 second timeout. It may be that 2 seconds will work with the code Hans posted, but you may want to do some additional testing. It is also possible that my HD-PVR is more sensitive to the timeout (i.e., slower to become ready). There is one other potential problem you may want to check. With my user-space restart, the mpeg stream consists of two (or more) concatenated streams. This causes some programs like vlc to have problems (e.g., doing forward jumps) since it only sees the length of the last of the streams. I'm not clear if this can also occur with your patch. Keith --- This email is free from viruses and malware because avast! Antivirus protection is active. http://www.avast.com -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
