Opened 5 years ago

Closed 4 years ago

#3517 closed defect (fixed)

can't set Video4Linux2 framerate

Reported by: nunojpg Owned by: holden
Priority: important Component: avdevice
Version: git-master Keywords: v4l2 regression
Cc: mywing81@gmail.com Blocked By:
Blocking: Reproduced by developer: yes
Analyzed by developer: no

Description

ffmpeg version N-61985-gd5c0036
built on Mar 31 2014 22:09:58 with gcc 4.8 (Ubuntu 4.8.2-17ubuntu2)
configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree

Linux sky5 3.13.0-20-generic #42-Ubuntu SMP Fri Mar 28 09:56:33 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

My webcam supports several framerates at 640x480.

If I try to grab it using:

./ffmpeg -f v4l2 -video_size 640x480 -framerate 5 -i /dev/video1 out1.avi

The webcam will continue with the 30fps selected (checked with v4l2-ctl -all), while ffmpeg will output the correct framerate, by droping every 5 in 6 frames.

This is a bug since ffmpeg tries to confirm the v4l2 accepts the selected framerate, but then does not select it:

./ffmpeg -f v4l2 -video_size 640x480 -framerate 3 -i /dev/video1 out3.avi
[video4linux2,v4l2 @ 0x32fca40] The driver changed the time per frame from 1/3 to 1/5

In this example v4l2 reports that the webcam does not support 3fps, and the closest value is 5fps. But 30fps will remain selected!

Current VLC HEAD does configure v4l2 framerate correctly.

Also the framerate is being set before the video_size, which introduces probably related errors.
The webcam under test supports hd1080@5fps, and hd720@10fps.
According to the following examples, it changes the framerate according to the video_size that was previously selected, and not the one that is currently being selected!

./ffmpeg -f v4l2 -video_size hd720 -framerate 10 -i /dev/video1 out.avi
(no errors)

./ffmpeg -f v4l2 -video_size hd1080 -framerate 10 -i /dev/video1 out.avi
(no errors)

./ffmpeg -f v4l2 -video_size hd1080 -framerate 10 -i /dev/video1 out.avi
[video4linux2,v4l2 @ 0x1f38a40] The driver changed the time per frame from 1/10 to 1/5

./ffmpeg -f v4l2 -video_size hd720 -framerate 10 -i /dev/video1 out.avi
[video4linux2,v4l2 @ 0x1d63a40] The driver changed the time per frame from 1/10 to 1/5

./ffmpeg -f v4l2 -video_size hd720 -framerate 10 -i /dev/video1 out.avi
(no errors)

Attachments (1)

0001-lavd-v4l2-revert-b1ad9312331759679a9c956233716a67ae6.patch (1.1 KB) - added by holden 4 years ago.

Download all attachments as: .zip

Change History (9)

comment:1 Changed 5 years ago by cehoyos

  • Keywords v4l2 added

To make this a valid ticket, please provide a failing command line together with the complete, uncut console output.

comment:2 Changed 5 years ago by nunojpg

nuno@sky5:~/Desktop/ffmpeg$  ./ffmpeg -f v4l2 -video_size 640x480 -framerate 5 -i /dev/video1 out1.avi
ffmpeg version N-61985-gd5c0036 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar 31 2014 22:09:58 with gcc 4.8 (Ubuntu 4.8.2-17ubuntu2)
  configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree
  libavutil      52. 70.100 / 52. 70.100
  libavcodec     55. 55.106 / 55. 55.106
  libavformat    55. 36.100 / 55. 36.100
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  5.102 /  2.  5.102
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, video4linux2,v4l2, from '/dev/video1':
  Duration: N/A, start: 851.587966, bitrate: 24576 kb/s
    Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 640x480, 24576 kb/s, 5 fps, 5 tbr, 1000k tbn, 1000k tbc
Output #0, avi, to 'out1.avi':
  Metadata:
    ISFT            : Lavf55.36.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 640x480, q=2-31, 200 kb/s, 5 tbn, 5 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> mpeg4)
Press [q] to stop, [?] for help
*** dropping frame 2 from stream 0 at ts 0
    Last message repeated 1 times
*** dropping frame 3 from stream 0 at ts 1
    Last message repeated 5 times
*** dropping frame 4 from stream 0 at ts 2
    Last message repeated 3 times
*** dropping frame 4 from stream 0 at ts 2time=00:00:00.80 bitrate= 972.7kbits/s dup=0 drop=12    
    Last message repeated 1 times
*** dropping frame 5 from stream 0 at ts 3
    Last message repeated 4 times
*** dropping frame 6 from stream 0 at ts 4
    Last message repeated 5 times
*** dropping frame 7 from stream 0 at ts 5time=00:00:01.20 bitrate= 838.5kbits/s dup=0 drop=25    
*** dropping frame 8 from stream 0 at ts 6
*** dropping frame 9 from stream 0 at ts 7
    Last message repeated 4 times
*** dropping frame 10 from stream 0 at ts 8
    Last message repeated 1 times
*** dropping frame 10 from stream 0 at ts 8ime=00:00:02.00 bitrate= 635.4kbits/s dup=0 drop=34    
    Last message repeated 1 times
*** dropping frame 11 from stream 0 at ts 9
    Last message repeated 3 times
*** dropping frame 12 from stream 0 at ts 10
    Last message repeated 3 times
*** dropping frame 12 from stream 0 at ts 10me=00:00:02.40 bitrate= 545.9kbits/s dup=0 drop=44    
*** dropping frame 13 from stream 0 at ts 11
    Last message repeated 3 times
*** dropping frame 14 from stream 0 at ts 12
    Last message repeated 2 times
*** dropping frame 15 from stream 0 at ts 13me=00:00:02.80 bitrate= 565.9kbits/s dup=0 drop=52    
    Last message repeated 1 times
*** dropping frame 16 from stream 0 at ts 14
    Last message repeated 1 times
*** dropping frame 17 from stream 0 at ts 15me=00:00:03.40 bitrate= 490.1kbits/s dup=0 drop=56    
    Last message repeated 2 times
*** dropping frame 19 from stream 0 at ts 17
*** dropping frame 20 from stream 0 at ts 18
*** dropping frame 20 from stream 0 at ts 18me=00:00:04.00 bitrate= 440.6kbits/s dup=0 drop=61    
*** dropping frame 21 from stream 0 at ts 19
    Last message repeated 1 times
*** dropping frame 22 from stream 0 at ts 20
    Last message repeated 1 times
*** dropping frame 23 from stream 0 at ts 21me=00:00:04.40 bitrate= 411.8kbits/s dup=0 drop=66    
    Last message repeated 2 times
*** dropping frame 24 from stream 0 at ts 22
    Last message repeated 1 times
frame=   24 fps=5.3 q=2.3 Lsize=     231kB time=00:00:04.80 bitrate= 394.2kbits/s dup=0 drop=71    
video:225kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 2.722515%
Received signal 2: terminating.
nuno@sky5:~/Desktop/ffmpeg$ v4l2-ctl -d 1 --all
Driver Info (not using libv4l2):
	Driver name   : uvcvideo
	Card type     : HD Pro Webcam C920
	Bus info      : usb-0000:00:1d.7-1
	Driver version: 3.13.7
	Capabilities  : 0x84000001
		Video Capture
		Streaming
		Device Capabilities
	Device Caps   : 0x04000001
		Video Capture
		Streaming
Priority: 2
Video input : 0 (Camera 1: ok)
Format Video Capture:
	Width/Height  : 640/480
	Pixel Format  : 'YUYV'
	Field         : None
	Bytes per Line: 1280
	Size Image    : 614400
	Colorspace    : SRGB
Crop Capability Video Capture:
	Bounds      : Left 0, Top 0, Width 640, Height 480
	Default     : Left 0, Top 0, Width 640, Height 480
	Pixel Aspect: 1/1
Streaming Parameters Video Capture:
	Capabilities     : timeperframe
	Frames per second: 30.000 (30/1)
	Read buffers     : 0
                     brightness (int)    : min=0 max=255 step=1 default=128 value=128
                       contrast (int)    : min=0 max=255 step=1 default=128 value=128
                     saturation (int)    : min=0 max=255 step=1 default=128 value=128
 white_balance_temperature_auto (bool)   : default=1 value=1
                           gain (int)    : min=0 max=255 step=1 default=0 value=200
           power_line_frequency (menu)   : min=0 max=2 default=2 value=2
      white_balance_temperature (int)    : min=2000 max=6500 step=1 default=4000 value=4793 flags=inactive
                      sharpness (int)    : min=0 max=255 step=1 default=128 value=128
         backlight_compensation (int)    : min=0 max=1 step=1 default=0 value=0
                  exposure_auto (menu)   : min=0 max=3 default=3 value=3
              exposure_absolute (int)    : min=3 max=2047 step=1 default=250 value=500 flags=inactive
         exposure_auto_priority (bool)   : default=0 value=1
                   pan_absolute (int)    : min=-36000 max=36000 step=3600 default=0 value=0
                  tilt_absolute (int)    : min=-36000 max=36000 step=3600 default=0 value=0
                 focus_absolute (int)    : min=0 max=250 step=5 default=0 value=0 flags=inactive
                     focus_auto (bool)   : default=1 value=1
                  zoom_absolute (int)    : min=100 max=500 step=1 default=100 value=100


In regard to the framerate being set before the video_size:

nuno@sky5:~/Desktop/ffmpeg$ ./ffmpeg -f v4l2 -video_size hd1080 -framerate 5 -i /dev/video1 file1.avi
ffmpeg version N-61985-gd5c0036 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar 31 2014 22:09:58 with gcc 4.8 (Ubuntu 4.8.2-17ubuntu2)
  configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree
  libavutil      52. 70.100 / 52. 70.100
  libavcodec     55. 55.106 / 55. 55.106
  libavformat    55. 36.100 / 55. 36.100
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  5.102 /  2.  5.102
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, video4linux2,v4l2, from '/dev/video1':
  Duration: N/A, start: 579.007577, bitrate: 165888 kb/s
    Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1920x1080, 165888 kb/s, 5 fps, 5 tbr, 1000k tbn, 1000k tbc
Output #0, avi, to 'file1.avi':
  Metadata:
    ISFT            : Lavf55.36.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1920x1080, q=2-31, 200 kb/s, 5 tbn, 5 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> mpeg4)
Press [q] to stop, [?] for help
frame=    8 fps=5.3 q=11.3 Lsize=     370kB time=00:00:01.80 bitrate=1682.4kbits/s    
video:364kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.584158%
Received signal 2: terminating.
nuno@sky5:~/Desktop/ffmpeg$ ./ffmpeg -f v4l2 -video_size hd720 -framerate 10 -i /dev/video1 file2.avi
ffmpeg version N-61985-gd5c0036 Copyright (c) 2000-2014 the FFmpeg developers
  built on Mar 31 2014 22:09:58 with gcc 4.8 (Ubuntu 4.8.2-17ubuntu2)
  configuration: --enable-libx264 --enable-gpl --enable-libfaac --enable-nonfree
  libavutil      52. 70.100 / 52. 70.100
  libavcodec     55. 55.106 / 55. 55.106
  libavformat    55. 36.100 / 55. 36.100
  libavdevice    55. 11.100 / 55. 11.100
  libavfilter     4.  3.100 /  4.  3.100
  libswscale      2.  5.102 /  2.  5.102
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
[video4linux2,v4l2 @ 0x1fcba40] The driver changed the time per frame from 1/10 to 1/5
Input #0, video4linux2,v4l2, from '/dev/video1':
  Duration: N/A, start: 591.103138, bitrate: 73728 kb/s
    Stream #0:0: Video: rawvideo (YUY2 / 0x32595559), yuyv422, 1280x720, 73728 kb/s, 5 fps, 5 tbr, 1000k tbn, 1000k tbc
Output #0, avi, to 'file2.avi':
  Metadata:
    ISFT            : Lavf55.36.100
    Stream #0:0: Video: mpeg4 (FMP4 / 0x34504D46), yuv420p, 1280x720, q=2-31, 200 kb/s, 5 tbn, 5 tbc
Stream mapping:
  Stream #0:0 -> #0:0 (rawvideo -> mpeg4)
Press [q] to stop, [?] for help
*** dropping frame 3 from stream 0 at ts 1
*** dropping frame 4 from stream 0 at ts 2
*** dropping frame 5 from stream 0 at ts 3time=00:00:00.80 bitrate=1553.1kbits/s dup=0 drop=2    
*** dropping frame 6 from stream 0 at ts 4
    Last message repeated 1 times
frame=    6 fps=5.7 q=4.6 Lsize=     185kB time=00:00:01.20 bitrate=1265.6kbits/s dup=0 drop=5    
video:180kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 3.166727%
Received signal 2: terminating.

If the second is considered to be a independent bug, I will open a new ticket if not fixed.

comment:3 follow-up: Changed 5 years ago by cehoyos

Does attached untested patch improve the situation?

comment:4 in reply to: ↑ 3 Changed 5 years ago by cehoyos

Replying to cehoyos:

Does attached untested patch improve the situation?

Sorry, please ignore this.

comment:5 Changed 4 years ago by holden

  • Cc mywing81@gmail.com added
  • Owner set to holden
  • Reproduced by developer set
  • Status changed from new to open

Hello, could you please test the attached patch and see if that solves the problem for you? Thanks.

comment:6 Changed 4 years ago by nunojpg

Patch works on top of git HEAD, v4l2 now gets the correct framerate selected.

The eventually related issue I also reported is also fixed with this (regarding the message: [video4linux2,v4l2 @ 0x1d63a40] The driver changed the time per frame from 1/10 to 1/5). So related they were.

Thanks!

comment:7 Changed 4 years ago by cehoyos

  • Keywords regression added
  • Priority changed from normal to important

Iiuc, this ticket describes a regression since b1ad9312331759679a9c956233716a67ae681d89

Last edited 4 years ago by cehoyos (previous) (diff)

comment:8 Changed 4 years ago by cehoyos

  • Resolution set to fixed
  • Status changed from open to closed

The commit was reverted by Michael in 6f21fb79

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