Re: [FFmpeg-user] USB Camera ffplay real-time and save to file

2020-09-11 Thread Simon Roberts
On Fri, Sep 11, 2020 at 7:13 AM Moritz Barsnick wrote: > On Fri, Sep 11, 2020 at 05:43:09 -0600, Simon Roberts wrote: > [...] > > > Use ffmpeg instead of ffplay to show the stream, [...] > > ffmpeg has several display output muxers/devices. The most common one &g

Re: [FFmpeg-user] USB Camera ffplay real-time and save to file

2020-09-11 Thread Simon Roberts
On Fri, Sep 11, 2020 at 1:18 AM Carl Eugen Hoyos wrote: > > > > Am 09.09.2020 um 23:07 schrieb Hans Carlson : > > > > I have a cheap USB pipe inspection camera and I want to see the output > (via ffplay) real-time, but also record (via ffmpeg) > > Use ffmpeg instead of ffplay to show the stream,

Re: [FFmpeg-user] Trouble grabbing from TV capture device

2020-08-27 Thread Simon Roberts
I was unclear: On Thu, Aug 27, 2020 at 2:52 PM Simon Roberts < si...@dancingcloudservices.com> wrote: > I have a little device that takes "old" composite video and sends it out > to USB. It's recognized by video4linux2 and I can watch the VHS tapes that > I'm trying to c

[FFmpeg-user] Trouble grabbing from TV capture device

2020-08-27 Thread Simon Roberts
ed something with a format, yet, nothing. Any idea how to proceed? Can I get more information from xawtv perhaps that might help me know how it's succeeding and transfer that info to ffmpeg? TIA, Simon -- Simon Roberts (303) 249 3613 ___ ffmpeg-user m

Re: [FFmpeg-user] Putting in a picture half-way through the video

2020-08-15 Thread Simon Roberts
On Sat, Aug 15, 2020 at 4:07 AM Cecil Westerhof wrote: > I have to publish the video's from our Zoom meetings. Something went > wrong. Halfway a recording the recording went from the speaker to the > overview screen. I like to change the part of the video with the > overview screen (people do

Re: [FFmpeg-user] Compression is a lot smaller

2020-08-15 Thread Simon Roberts
On Sat, Aug 15, 2020 at 5:01 AM Cecil Westerhof wrote: > Through scripts I use ffmpeg for cutting and compressing videos and > sometimes adding a watermark. Nothing fancy, but handy. > > In the past the original file was between 4 to 13 times bigger as the > compressed file. Today I compressed a

Re: [FFmpeg-user] directly view transcoding in video player

2020-08-07 Thread Simon Roberts
On Fri, Aug 7, 2020 at 7:31 AM James Darnley wrote: > On 07/08/2020, Timothy W. Grove wrote: > > I develop an application which displays a video, amongst other things. A > > user may open just about any video format to view in the video display. > > "Saving" a video will invoke ffmpeg to resize

Re: [FFmpeg-user] Rescuing inconsistent frame rate screen capture file?

2020-07-28 Thread Simon Roberts
frames from a source that has radically varying frame rates. On Thu, Jul 23, 2020 at 1:23 PM Simon Roberts wrote: > > Hi all, I have some video files (video only, no audio) that were > recorded using ffmpeg to capture a computer screen. Unfortunately, it > seems that the frame rate is some

[FFmpeg-user] Rescuing inconsistent frame rate screen capture file?

2020-07-23 Thread Simon Roberts
is what might cause this (it's an x11grab input through libx264, and was using about 2.5 of the 4 cores the machine has.) and how might I know that it's failing while the recording is taking place? TIA, Simon -- Simon Roberts (303) 249 3613 ___ ffmpeg-user

Re: [FFmpeg-user] Fwd: Understanding/preventing buffer overruns

2020-07-20 Thread Simon Roberts
> > [...snip, mostly successful scenario describing simultaneous recording > > of four video channels...] > > > >> 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

[FFmpeg-user] Fwd: Understanding/preventing buffer overruns

2020-07-20 Thread Simon Roberts
[...snip, mostly successful scenario describing simultaneous recording of four video channels...] > 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

[FFmpeg-user] How to set alsa audio sample format

2020-07-17 Thread Simon Roberts
, like s16, s32, s16p and more. I tried every one of these values after -sample_fmt on my command line and every one of them was rejected as "cannot set sample format 0x1 2". Any guidance would be greatly appreciated. -- Simon Roberts (303

[FFmpeg-user] Understanding/preventing buffer overruns

2020-07-16 Thread Simon Roberts
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

Re: [FFmpeg-user] Causes of color bars?

2020-07-15 Thread Simon Roberts
On Wed, Jul 15, 2020 at 1:36 AM Marton Balint wrote: > On Wed, 15 Jul 2020, Moritz Barsnick wrote: > > On Tue, Jul 14, 2020 at 15:50:55 -0600, Simon Roberts wrote: > >> On Tue, Jul 14, 2020 at 1:29 AM Carl Zwanzig wrote: > >> > >> > Decklink boards are _ve

Re: [FFmpeg-user] Causes of color bars?

2020-07-14 Thread Simon Roberts
> > > Decklink boards are _very_ touchy about formats and parameters. Try > > > setting > > > at least the resolution and frame rate on the input and see if that helps. > > > > > > I don't guarantee these, but it's a start: > > > -f decklink -pix_fmt uyvy422 -s 720x486 -r 3/1001 "DeckLink SDI

Re: [FFmpeg-user] Causes of color bars?

2020-07-14 Thread Simon Roberts
On Tue, Jul 14, 2020 at 1:29 AM Carl Zwanzig wrote: > Decklink boards are _very_ touchy about formats and parameters. Try setting > at least the resolution and frame rate on the input and see if that helps. > > I don't guarantee these, but it's a start: > -f decklink -pix_fmt uyvy422 -s 720x486

Re: [FFmpeg-user] Causes of color bars?

2020-07-14 Thread Simon Roberts
, 2020 at 8:50 AM Devin Heitmueller < devin.heitmuel...@ltnglobal.com> wrote: > On Tue, Jul 14, 2020 at 10:41 AM Simon Roberts > wrote: > > > > Well, I found out more. If I connect the camera to the input through the > > cabling, but remove the splitter, it w

[FFmpeg-user] Reducing latency?

2020-07-14 Thread Simon Roberts
I have two situations where I'm noticing significant latency, and I'd like to know what to investigate with a view to perhaps reducing this. 1) When running ffplay (attached to a camera), the video I watch is about a full second behind the "real world". 2) When recording multiple video channels,

Re: [FFmpeg-user] Causes of color bars?

2020-07-14 Thread Simon Roberts
, but ffmpeg doesn't see it. Could the splitter be changing the pixel format? I'll read about those and see if I can move forward that way. On Tue, Jul 14, 2020 at 7:17 AM Simon Roberts < si...@dancingcloudservices.com> wrote: > Thanks Paul and Marton for the input. I will note that the simpl

Re: [FFmpeg-user] Causes of color bars?

2020-07-14 Thread Simon Roberts
" > -preset superfast -crf 18 -minrate 8M -maxrate 8M -bufsize 10M -acodec > libfdk_aac -vcodec libx264 -r 30 -f flv rtmp://x.com > > Hope that helps > > Regards, > Paul > > > On 14 Jul 2020, at 02:28, Simon Roberts > wrote: > > > > Hi all,

[FFmpeg-user] Causes of color bars?

2020-07-13 Thread Simon Roberts
Hi all, I've been working with a Decklink Quad HDMI card under Ubuntu 20.04. The kernel driver is loaded and the Blackmagic software "mediaexpress" displays the input signal perfectly. However, when I try to use ffplay, it seems like it knows which of the four channels on the card has a signal,

Re: [FFmpeg-user] Audio sample format in alsa?

2020-07-01 Thread Simon Roberts
On Wed, Jul 1, 2020 at 12:22 PM Nicolas George wrote: > Simon Roberts (12020-07-01): > > Magic! plughw:1,0 works a treat. Are there any limitations, or caveats, > > that I should be aware of? Is this a risk or tradeoff of any sort? I note > > that the recording seems

Re: [FFmpeg-user] Audio sample format in alsa?

2020-07-01 Thread Simon Roberts
On Wed, Jul 1, 2020 at 5:00 AM Nicolas George wrote: > Simon Roberts (12020-06-30): > > I get: > > [alsa @ 0x55ac7254fd80] cannot set sample format 0x1 2 (Invalid > > argument) > > hw:1,0: Input/output error > > This message could be made better. This is

[FFmpeg-user] Audio sample format in alsa?

2020-06-30 Thread Simon Roberts
I'm trying to grab audio from a USB device that's managed by alsa. I find that if I configure pulse to use this device, then I can grab successfully with: ffmpeg -f alsa -i pulse audiotest.mp3 But I need to refer to the hardware device directly, and I'm failing to do that. I have these cards:

Re: [FFmpeg-user] Low CPU HQ format for local streaming?

2020-06-30 Thread Simon Roberts
> > > > > I need to find an encoding, and presumably a file type, that a) works in > a > > streaming format, and b) is as low CPU usage as possible. I don't > believe I > > care about bandwidth, this is just shipped from one process to another > and > > consumed in real time. > > > > I tried using

[FFmpeg-user] Low CPU HQ format for local streaming?

2020-06-30 Thread Simon Roberts
s for a very low CPU overhead, but not caring about bandwidth, for this? TIA, Simon -- Simon Roberts (303) 249 3613 ___ ffmpeg-user mailing list ffmpeg-user@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-user To unsubscribe, visit link above, or em

[FFmpeg-user] Stream during capture/compress?

2020-06-29 Thread Simon Roberts
I would like to get a live monitor of the output of an ffmpeg process (it's actually a capture and compress process). I believe I could achieve this by adding a streaming output, and then separately starting an ffplay process to display that (I haven't tried this yet, but have got most of the

Re: [FFmpeg-user] "Four up" output?

2020-06-27 Thread Simon Roberts
On Sat, Jun 27, 2020 at 10:02 AM Carl Zwanzig wrote: > On 6/27/2020 8:53 AM, Simon Roberts wrote: > > 1) create a composite output that has all four of the inputs laid out one > > per quadrant, so all can be seen on a single display > > Google "ffmpeg multiviewer",

[FFmpeg-user] "Four up" output?

2020-06-27 Thread Simon Roberts
I'm now able to take four input streams from my Blackmagic quad input card and successfully map them into a single compressed output file. What I'd like to do next is to "tee-off" a monitoring stream (literally for live viewing). There are two features I'd like for this: 1) create a composite

Re: [FFmpeg-user] Streaming quality

2020-06-27 Thread Simon Roberts
On Sat, Jun 27, 2020 at 1:46 AM Carl Eugen Hoyos wrote: > > Am 27.06.2020 um 05:26 schrieb Simon Roberts < > si...@dancingcloudservices.com>: > > > > ffmpeg -i -f mpegts tcp://192.168.1.109:2000 > > Either specify a constant quantiser with “-qscale 10 -mbd 2” o

[FFmpeg-user] Streaming quality

2020-06-26 Thread Simon Roberts
quality of the image? Many thanks, Simon -- Simon Roberts (303) 249 3613 ___ 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] Capture multiple streams into same container?

2020-06-24 Thread Simon Roberts
On Wed, Jun 24, 2020 at 4:26 PM Tom Sparks wrote: > On 25/06/2020, Simon Roberts wrote: > > On Wed, Jun 24, 2020 at 3:41 AM Tom Sparks > wrote: > > > >> mkv is a better output format to use > >> > > > > Thanks for this Tom, can you expand

Re: [FFmpeg-user] Capture multiple streams into same container?

2020-06-24 Thread Simon Roberts
nt into it, just "what somebody said" :) > On 24/06/2020, Simon Roberts wrote: > > Greetings all, I'm a pretty low-level ffmpeg user, just doing screen > > captures, compressions, and some simple format conversions. I have not > made > > much progress und

Re: [FFmpeg-user] Capture multiple streams into same container?

2020-06-24 Thread Simon Roberts
On Wed, Jun 24, 2020 at 5:43 AM Moritz Barsnick wrote: > On Tue, Jun 23, 2020 at 21:31:25 -0600, Simon Roberts wrote: > > But I have no clue how to start with this. I tried simply adding more > input > > channels to my input specifications: > [... elided my incorrect command

[FFmpeg-user] Capture multiple streams into same container?

2020-06-23 Thread Simon Roberts
) Can someone point me at a template for a command line that might do what I need? If the explanation or resources might help me understand the concepts better, that would be a bonus (and might result in my becoming a little more self-sufficient!) Cheers, Simon -- Simon Roberts (303) 249 3613