Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
Jim DeLaHunt-2 wrote > It seems like this is a question for the playback app, not for ffmpeg. > What are you using to play back the video? VLC? FFplay? Whatever player > the PS/3 has? I'm on Linux (Mint) and I've used VLC and Xplayer; on the PS/3 it's whatever it uses natively to play the mp4 file. Since they all show the same behaviour, the common factor would appear to be the mp4 file, not the player. The 720x576 video is a broadcast transmission recorded on a Humax box. The 1280x720 video is the output from OpenShot after editing the same file. I've found that if I use the scale function in OpenShot and export the video using a scale factor of 1.4 on both dimensions I get a video that plays with the full horizontal width, and is still 1280x720 i.e. the scaling has done something other than increase the number of pixels, and I don't understand what this is. OpenShot does not set the DAR in the exported file, I have to set it subsequently using ffmpeg, but then I get a file that plays pretty much like the original. I agree it's not an ffmpeg issue /per se/, but I'm hoping that with the video knowledge around this forum someone can tell me what the issue is and how to fix it using ffmpeg. Chris -- Sent from: http://www.ffmpeg-archive.org/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On 07/16/2020 02:04 AM, fowman wrote: Jim DeLaHunt-2 wrote It seems like this is a question for the playback app, not for ffmpeg. What are you using to play back the video? VLC? FFplay? Whatever player the PS/3 has? I'm on Linux (Mint) and I've used VLC and Xplayer; on the PS/3 it's whatever it uses natively to play the mp4 file. Since they all show the same behaviour, the common factor would appear to be the mp4 file, not the player. Isn't there another common factor? How about the display device? Are you playing to the same TV? Can that TV scale up 1280x720? ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] New VVC codec issues
Hi Deian, On Thu, Jul 16, 2020 at 07:16:08 +, FFmpeg user discussions wrote: > Hi ! > I have some VVC (versatile video codec) files and wanted to run some tests to > see how much computational power is needed to decode them. The FFmpeg does > not recognize the stream, even when i use the copy_unknown command it does > nothing and also asks for an output container format ( i want the raw stream > on a .bin file). The issue is discussed here : > r/VVC - No way found to play vvc files We can't really read your e-mail. Here's how wo see it on the list: http://ffmpeg.org/pipermail/ffmpeg-user/2020-July/049381.html Is it this thread? https://www.reddit.com/r/VVC/comments/hputue/no_way_found_to_play_vvc_files/ Kindly describe your problem directly here. Thanks, Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] New VVC codec issues
On Thu, Jul 16, 2020 at 09:45:56 +0200, Moritz Barsnick wrote: > Hi Deian, [...] > Is it this thread? > https://www.reddit.com/r/VVC/comments/hputue/no_way_found_to_play_vvc_files/ > > Kindly describe your problem directly here. Ah, is VCC identical with H.266? Yet another patent encumbered next generation codec with the same issues as H.265, trying to compete with VP10 and AV1 and AV2. ffmpeg doesn't have support for that yet. Patch welcome. Perhaps if the MPEG consortium could provide a free, open reference decoder implementation? Just dreaming... Cheers, Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] New VVC codec issues
On Thu, Jul 16, 2020 at 10:02:17 +0200, Moritz Barsnick wrote: > ffmpeg doesn't have support for that yet. Patch welcome. Perhaps if the > MPEG consortium could provide a free, open reference decoder > implementation? Just dreaming... My bad, that Reddit does point to the Fraunhofer implementation, which is under a BSD license (but still would need to be evaluated whether it is "free" in ffmpeg's terms). Anyway, still no support in ffmpeg yet. ;-) I'll have a look whether I can manage to use the Fraunhofer tools on those files, and whether I can convice ffmpeg to export the raw stream: > The FFmpeg does not recognize the stream, even when i use the > copy_unknown command it does nothing and also asks for an output > container format ( i want the raw stream on a .bin file). Probably with "-map 0:s -c:s copy -f rawvideo output.bin", assuming it's recognized as a data stream(?). I will try myself. Please always show us the command line you tried and its complete uncut console output. Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] New VVC codec issues
From what I've seen, it is functionally an expansion on 265 in the same way that 265 was an expansion on 264. And yes, the same political problems attend it that also attended 265, and no real effort has been made to solve those problems. As such it's probably irrelevant how good it is because no bugger's going to use it anyway. P On Thursday, 16 July 2020, 09:02:29 BST, Moritz Barsnick wrote: On Thu, Jul 16, 2020 at 09:45:56 +0200, Moritz Barsnick wrote: > Hi Deian, [...] > Is it this thread? > https://www.reddit.com/r/VVC/comments/hputue/no_way_found_to_play_vvc_files/ > > Kindly describe your problem directly here. Ah, is VCC identical with H.266? Yet another patent encumbered next generation codec with the same issues as H.265, trying to compete with VP10 and AV1 and AV2. ffmpeg doesn't have support for that yet. Patch welcome. Perhaps if the MPEG consortium could provide a free, open reference decoder implementation? Just dreaming... Cheers, Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] New VVC codec issues
Hi ! I have some VVC (versatile video codec) files and wanted to run some tests to see how much computational power is needed to decode them. The FFmpeg does not recognize the stream, even when i use the copy_unknown command it does nothing and also asks for an output container format ( i want the raw stream on a .bin file). The issue is discussed here : r/VVC - No way found to play vvc files | | | | || | | | | | r/VVC - No way found to play vvc files 1 vote and 4 comments so far on Reddit | | | | Thanks. ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
Mark Filipak wrote > Isn't there another common factor? How about the display device? Are you > playing to the same TV? Can > that TV scale up 1280x720? VLC and Xplayer are playing to my computer screen, and the PS/3 to my TV, so no, not the same. With the small mp4 (1280x720) playing through the PS/3, I can change the TV display settings with "stretch" or "best fit" etc options to make the picture bigger, but with the normal settings it's just a rectangle that doesn't fill the screen. The TV is full HD 1080p. Are you suggesting that the players may up-scale automatically under certain circumstances? I can see how that's possible, but if so, are these circumstances "standard" so that the players all behave in the same way, and could I know what they are so I can engineer a predictable result? Thanks, Chris -- Sent from: http://www.ffmpeg-archive.org/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
Moritz Barsnick wrote > Only the PS/3 is the issue, right? No, I have the same on all three. -- Sent from: http://www.ffmpeg-archive.org/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On Thu, Jul 16, 2020 at 07:22:39 -0500, fowman wrote: > No, I have the same on all three. Ah, okay. *All* you players are able to scale the 720x576 video to fullscreen (automatically?), and *NONE* of them manages that with the 1280x720 video? That seems very unlikely. With every 1280x720 video? Or just this one? I'm guessing the latter video is letterboxed, i.e. a large black box around it is encoded in the video. If you can share, we could tell. If not, I know of no such property which would prevent such a video from being scaled. Generally speaking, all these players should somehow decode into a framebuffer, and then scale that, regardless of what the original video file says. Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On Thu, Jul 16, 2020 at 09:20:31 -0400, Edward Park wrote: > I don't know if they are not used in all players but MP4 file format > can contain the "clean-aperture" region info as well as matrices to > specify sample transformations before the presentation should be > displayed by default. Ah, interesting. At the same time, VLC's trac ticket system indicates that this has not been implemented in VLC. (ffmpeg doesn't tell me about this, while mediainfo shows both dimensions.) [*] I stand with my remarks: > > With every 1280x720 video? Or just this one? > [...] > > If you can share, we could tell. Moritz [*] https://trac.videolan.org/vlc/ticket/21179 https://streams.videolan.org/issues/21179/clap.mov ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On Thu, Jul 16, 2020 at 06:55:55 -0500, fowman wrote: > VLC and Xplayer are playing to my computer screen, and the PS/3 to my TV, so > no, not the same. Only the PS/3 is the issue, right? > With the small mp4 (1280x720) playing through the PS/3, I can change the TV > display settings with "stretch" or "best fit" etc options to make the > picture bigger, but with the normal settings it's just a rectangle that > doesn't fill the screen. The TV is full HD 1080p. > > Are you suggesting that the players may up-scale automatically under certain > circumstances? I can see how that's possible, but if so, are these > circumstances "standard" so that the players all behave in the same way, and > could I know what they are so I can engineer a predictable result? This is only an issue between your player and your screen, from all I have read here. If their configurations don't match, you won't get a full-screen display. This has nothing to do with any "settings" or metadata in the video file. Here are the PS/3 settings for upscaling, if you TV doesn't manage: Games: https://manuals.playstation.net/document/en/ps3/current/settings/gamesettings.html DVD/BD: https://manuals.playstation.net/document/en/ps3/3_15/settings/bdsettings.html I can't find any settings for the video player, but it should have some as well, or one of the above might apply? Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
Hi, > On Jul 16, 2020, at 08:39, Moritz Barsnick wrote: > > On Thu, Jul 16, 2020 at 07:22:39 -0500, fowman wrote: >> No, I have the same on all three. > > Ah, okay. *All* you players are able to scale the 720x576 video to > fullscreen (automatically?), and *NONE* of them manages that with the > 1280x720 video? That seems very unlikely. With every 1280x720 video? Or > just this one? > > I'm guessing the latter video is letterboxed, i.e. a large black box > around it is encoded in the video. If you can share, we could tell. > > If not, I know of no such property which would prevent such a video > from being scaled. Generally speaking, all these players should somehow > decode into a framebuffer, and then scale that, regardless of what the > original video file says. > > Moritz I don't know if they are not used in all players but MP4 file format can contain the "clean-aperture" region info as well as matrices to specify sample transformations before the presentation should be displayed by default. Regards, Ted Park ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On 16/07/2020 14:22, fowman wrote: > Moritz Barsnick wrote >> Only the PS/3 is the issue, right? > > No, I have the same on all three. > > Does your video not need [black bar] cropping? Easiest is to open in HandBrake and select Preview, then Show Crop. -- PeterVDH ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] hevc_vaapi mkv output fails with generic error
Hi Haihao, The question is why this is not possible at all since it was possible already on an older system. I kinda don't understand where these warnings come from ... maybe the amdgpu Kernel driver? Anyway ... encoding with libx265 is possible but for my purpose far to slow even with all cores. Best regards, Andreas Am 11.07.2020 um 15:43 schrieb Xiang, Haihao: > According to the your debug output below, the encoded stream is not muxable to > some containers, maybe this the root cause of your issue. > > [hevc_vaapi @ 0x5239bc0] Driver does not support some wanted packed headers > (wanted 0xd, found 0). > [hevc_vaapi @ 0x5239bc0] Driver does not support packed sequence headers, but > a > global header is requested. > [hevc_vaapi @ 0x5239bc0] No global header will be written: this may result in > a > stream which is not usable for some purposes (e.g. not muxable to some > containers). > > Thanks > Haihao > >> Hello everyone, >> >> I am currently unable to transcode H264 MKV to HEVC MKV on an AMD Ryzen >> 3400G running openSuSE Leap 15.2. >> >> Using following command >> >> ffmpeg -loglevel debug -vaapi_device /dev/dri/renderD128 -hwaccel vaapi >> -hwaccel_output_format vaapi -i sample.mkv -c:v hevc_vaapi -vf >> 'hwdownload,format=nv12,hwupload' -rc_mode 3 -b:v 3M -profile:v 1 -tier >> 1 -level 153 -c:a copy output.mkv >> >> I am getting follwing error message >> >> [AVHWFramesContext @ 0x52a3cc0] Created surface 0x22. >> [AVHWFramesContext @ 0x52a3cc0] Direct mapping disabled: deriving image >> does not work: 1 (operation failed). >> [matroska @ 0x5235ec0] get_metadata_duration returned: 0 >> Could not write header for output file #0 (incorrect codec parameters >> ?): Invalid data found when processing input >> Error initializing output stream 0:0 -- >> [AVIOContext @ 0x5209740] Statistics: 0 seeks, 1 writeouts >> [AVIOContext @ 0x5284400] Statistics: 197393 bytes read, 2 seeks >> >> FFmpeg static build by myself. >> >> Is there anyone who can help me understanding what is going on here and >> how to get this working? >> I am breaking my head for 3 days now trying to solve this issue. >> >> Full debug output here: https://pastebin.com/khp5g9F5 >> < >> https://deref-web.de/mail/client/gxpESspRx9g/dereferrer/?redirectUrl=https%3A%2F%2Fpastebin.com%2Fkhp5g9F5 >> >> Best regards, >> Andreas >> ___ >> ffmpeg-user mailing list >> ffmpeg-user@ffmpeg.org >> https://ffmpeg.org/mailman/listinfo/ffmpeg-user >> >> To unsubscribe, visit link above, or email >> ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". > ___ > ffmpeg-user mailing list > ffmpeg-user@ffmpeg.org > https://ffmpeg.org/mailman/listinfo/ffmpeg-user > > To unsubscribe, visit link above, or email > ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On 07/16/2020 01:39 PM, fowman wrote: Moritz Barsnick wrote With every 1280x720 video? Or just this one? Just this, but then it's the only one I have :-) I'm guessing the latter video is letterboxed, i.e. a large black box around it is encoded in the video. If you can share, we could tell. -snip- I realise that the original .ts video is actually letterboxed, although the vertical side bars are pretty narrow. I've always assumed that letterboxing referred to the top and bottom horizontal bars -snip- You are correct regarding letterbox. What you see, black areas top-bottom-left-right, is called "pillarbox". ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
Moritz Barsnick wrote > With every 1280x720 video? Or just this one? Just this, but then it's the only one I have :-) > I'm guessing the latter video is letterboxed, i.e. a large black box > around it is encoded in the video. If you can share, we could tell. Yes it is. My description of being displayed in a small rectangle was trying to say this. I'm struggling to describe the problem in the correct terminology so please bear with me. Here is ffprobe info: Original .ts file recorded by my Humax: Stream #0:0[0x931]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), yuv420p(tv), 704x576 [SAR 16:11 DAR 16:9], max. 15000 kb/s, 25 fps, 25 tbr, 90k tbn, 50 tbc 1280x720 .mp4 exported from OpenShot: Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, 14925 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default) The OpenShot export parameters used DAR 16:9 and Pixel Ratio (which I assume is the same as SAR) of 64:45, although it doesn't set the DAR or SAR in the file metadata (I did this subsequently with ffnpeg). I realise that the original .ts video is actually letterboxed, although the vertical side bars are pretty narrow. I've always assumed that letterboxing referred to the top and bottom horizontal bars and was just a side effect of playing a widescreen movie in a 16:9 or 4:3 display. I also did wonder how the how this original movie played with the correct (at least correct looking) AR when the DAR is set to 16:9 - the measured AR on my computer screen is more like 24:10. So it occurred to me - has this video been letterboxed to play in an AR of 16:9 when its real AR is greater? -- Sent from: http://www.ffmpeg-archive.org/ ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
Re: [FFmpeg-user] How do I increase the playback size of a video without rescaling it?
On Thu, Jul 16, 2020 at 12:39:03 -0500, fowman wrote: > Just this, but then it's the only one I have :-) It can't be that difficult to find other 1280x720 recodings, can it? Or to create your own? > Here is ffprobe info: > > Original .ts file recorded by my Humax: > Stream #0:0[0x931]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002), > yuv420p(tv), 704x576 [SAR 16:11 DAR 16:9], max. 15000 kb/s, 25 fps, 25 tbr, > 90k tbn, 50 tbc > > 1280x720 .mp4 exported from OpenShot: > Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720, > 14925 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default) That doesn't tell me whether the content includes boxes. Unless you run it through the cropdetect filter. > I realise that the original .ts video is actually letterboxed, although the > vertical side bars are pretty narrow. I've always assumed that letterboxing > referred to the top and bottom horizontal bars and was just a side effect of > playing a widescreen movie in a 16:9 or 4:3 display. I'm not referring to a side effect. I meant true black "boxes" or borders, included in the encoded frames. What often used to happen was that (true) 16:9 content was amended with bars to make it 4:3. If you then play that (4:3 enconding) fullscreen on a 16:9 screen, you will have the explicit top/bottom bars, and newly introduced left/right bars, to fill the encoded 4:3 back up to 16:9, instead of snipping something away, obviously. In total, this would give you a big box around your content, despite full screen. In your case, there might be a big box there (which we could see if we saw the actual viedo), or said "clean-aperture" (CLAP) marking, which could have funny effects. Come to think of it, those effects should be opposite, i.e. the clean aperture should enforce cropping of non-displayable segments. Moritz ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] Ffmpeg issues multiple HTTP requests when starting a video from a URL
I'm using ffmpeg to read an mp4 video from a HTTP URL and in some cases it issues up to 3 HTTP calls before it actually starts the conversion. There is no attempt to seek the video on the command line. The server returns HTTP/1.1 206 Partial Content initially and ffmpeg then tries to get data at different offsets before it prints "All info found" and proceeds with the conversion. Multiple connections cause an additional delay which I'd like to avoid no matter how small it is. Is there a mechanism to override this behavior and have ffmpeg to work with the data stream as it is being read? I'm using version 4.2.1. Thanks. -Vlad ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
[FFmpeg-user] Understanding/preventing buffer overruns
Hi all, I have a recording configuration going that's grabbing three 1080 30p inputs and one 720 30p input simultaneously, and seems to be capable of either prores or libx264 crf 23 compressions. The resulting video appears to be smooth, and when I include a clock in one of the streams, it maintains good time over a couple of minutes of test. But... I get almost continuous buffer overruns after about a minute. Can someone tell me where to start learning about how I might fix this (I presume it can't be good that it's doing this even though the output seems to be OK, right?) One negative thing I notice is that when I play this back with VLC it complains about timestamps (and some other complaints about recursion and decoder hardware that I don't think are related to this) [7fc4251af680] main decoder error: Could not convert timestamp 4637816048 for FFmpeg [7fc425099d20] main decoder error: Timestamp conversion failed (delay 100, buffering 10, bound 900) [7fc425099d20] main decoder error: Could not convert timestamp 4637849382 for FFmpeg [7fc4251a19f0] main decoder error: Timestamp conversion failed (delay 100, buffering 10, bound 900) these repeat extensively Here's a sample of the messages during recording (which also repeat essentially continuously) [decklink @ 0x55b2249e8580] Decklink input buffer overrun! Last message repeated 1 times [decklink @ 0x55b2249a4040] Decklink input buffer overrun!944kB time=00:00:52.30 bitrate=549308.8kbits/s dup=35 drop=4048 speed=0.999x [decklink @ 0x55b2249e8580] Decklink input buffer overrun! Last message repeated 13 times Can anyone point me at what part of the documentation might address this, or better still give me hints? TIA, Simon ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or email ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".