[FFmpeg-user] Capture from USB Dazzle: *** dropping frames

[MrNice]

I managed to get an "old" DVD player to test again.
Now the only issue I get is a lot of
"Cliping frame in rate conversion by "

As the text is green, I'd say this is not important.
Could you please confirm and shortly explain what means this sentence.
I could not understand when reading the source code.


Second question
I had to add -ts to sync audio and video. I tried with -ts abs and -ts
mono2abs. I have read the documentation but a bit hard to understand.
Both are working but what is the difference, which one do you advice?

Thanks

 ./ffmpeg -debug 1 -f pulse -ar 44100 -ac 2 -channel_layout stereo
-thread_queue_size 512 -i alsa_input.pci-0000_00_14.2.analog-stereo -f
v4l2 -ts mono2abs -channel 1 -video_size 720x576 -pix_fmt yuyv422
-thread_queue_size 512 -i /dev/video0 -c:v ffv1 -level 3 -pix_fmt
yuv422p -c:a pcm_s16le /Store3/Test/t_`date +%Y%m%d_%H%M`.mkv
ffmpeg version N-73832-g736a386 Copyright (c) 2000-2015 the FFmpeg
developers
  built with gcc 5.1.1 (GCC) 20150618 (Red Hat 5.1.1-4)
  configuration: --enable-libpulse --enable-gpl --enable-libx264
  libavutil      54. 28.100 / 54. 28.100
  libavcodec     56. 49.101 / 56. 49.101
  libavformat    56. 40.101 / 56. 40.101
  libavdevice    56.  4.100 / 56.  4.100
  libavfilter     5. 25.100 /  5. 25.100
  libswscale      3.  1.101 /  3.  1.101
  libswresample   1.  2.101 /  1.  2.101
  libpostproc    53.  3.100 / 53.  3.100
 matched as AVOption 'debug' with argument '1'.
Reading option '-f' ... matched as option 'f' (force format) with
argument 'pulse'.
Reading option '-ar' ... matched as option 'ar' (set audio sampling rate
(in Hz)) with argument '44100'.
Reading option '-ac' ... matched as option 'ac' (set number of audio
channels) with argument '2'.
Reading option '-channel_layout' ... matched as option 'channel_layout'
(set channel layout) with argument 'stereo'.
Reading option '-thread_queue_size' ... matched as option
'thread_queue_size' (set the maximum number of queued packets from the
demuxer) with argument '512'.
Reading option '-i' ... matched as input file with argument
'alsa_input.pci-0000_00_14.2.analog-stereo'.
Reading option '-f' ... matched as option 'f' (force format) with
argument 'v4l2'.
Reading option '-ts' ... matched as AVOption 'ts' with argument 'mono2abs'.
Reading option '-channel' ... matched as AVOption 'channel' with
argument '1'.
Reading option '-video_size' ... matched as AVOption 'video_size' with
argument '720x576'.
Reading option '-pix_fmt' ... matched as option 'pix_fmt' (set pixel
format) with argument 'yuyv422'.
Reading option '-thread_queue_size' ... matched as option
'thread_queue_size' (set the maximum number of queued packets from the
demuxer) with argument '512'.
Reading option '-i' ... matched as input file with argument '/dev/video0'.
Reading option '-c:v' ... matched as option 'c' (codec name) with
argument 'ffv1'.
Reading option '-level' ... matched as AVOption 'level' with argument '3'.
Reading option '-pix_fmt' ... matched as option 'pix_fmt' (set pixel
format) with argument 'yuv422p'.
Reading option '-c:a' ... matched as option 'c' (codec name) with
argument 'pcm_s16le'.
Reading option '/Store3/Test/t_20150801_1735.mkv' ... matched as output
file.
Finished splitting the commandline.
Parsing a group of options: global .
Successfully parsed a group of options.
Parsing a group of options: input file
alsa_input.pci-0000_00_14.2.analog-stereo.
Applying option f (force format) with argument pulse.
Applying option ar (set audio sampling rate (in Hz)) with argument 44100.
Applying option ac (set number of audio channels) with argument 2.
Applying option channel_layout (set channel layout) with argument stereo.
Applying option thread_queue_size (set the maximum number of queued
packets from the demuxer) with argument 512.
Successfully parsed a group of options.
Opening an input file: alsa_input.pci-0000_00_14.2.analog-stereo.
[pulse @ 0x28f7dc0] All info found
Input #0, pulse, from 'alsa_input.pci-0000_00_14.2.analog-stereo':
  Duration: N/A, start: 1438446921.636832, bitrate: 1411 kb/s
    Stream #0:0, 1, 1/1000000: Audio: pcm_s16le, 44100 Hz, stereo, s16,
1411 kb/s
Successfully opened the file.
Parsing a group of options: input file /dev/video0.
Applying option f (force format) with argument v4l2.
Applying option pix_fmt (set pixel format) with argument yuyv422.
Applying option thread_queue_size (set the maximum number of queued
packets from the demuxer) with argument 512.
Successfully parsed a group of options.
Opening an input file: /dev/video0.
[video4linux2,v4l2 @ 0x2910ec0] fd:6 capabilities:85220001
[video4linux2,v4l2 @ 0x2910ec0] Selecting input_channel: 1
[video4linux2,v4l2 @ 0x2910ec0] Current input_channel: 1, input_name:
S-Video, input_std: ffffff
[video4linux2,v4l2 @ 0x2910ec0] The V4L2 driver is using the interlaced mode
[video4linux2,v4l2 @ 0x2910ec0] Current standard: PAL, id: ff,
frameperiod: 1/25
[video4linux2,v4l2 @ 0x2910ec0] Detected monotonic timestamps, converting
[video4linux2,v4l2 @ 0x2910ec0] All info found
Input #1, video4linux2,v4l2, from '/dev/video0':
  Duration: N/A, start: 1438446922.767573, bitrate: 165888 kb/s
    Stream #1:0, 1, 1/1000000: Video: rawvideo, 1 reference frame (YUY2
/ 0x32595559), yuyv422, 720x576, 1/1000000, 165888 kb/s, 25 fps, 25 tbr,
1000k tbn, 1000k tbc
Successfully opened the file.
Parsing a group of options: output file /Store3/Test/t_20150801_1735.mkv.
Applying option c:v (codec name) with argument ffv1.
Applying option pix_fmt (set pixel format) with argument yuv422p.
Applying option c:a (codec name) with argument pcm_s16le.
Successfully parsed a group of options.
Opening an output file: /Store3/Test/t_20150801_1735.mkv.
Successfully opened the file.
detected 8 logical cores
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'video_size' to
value '720x576'
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'pix_fmt' to value '1'
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'time_base' to value
'1/1000000'
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'pixel_aspect' to
value '0/1'
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'sws_param' to value
'flags=2'
[graph 0 input from stream 1:0 @ 0x28d9860] Setting 'frame_rate' to
value '25/1'
[graph 0 input from stream 1:0 @ 0x28d9860] w:720 h:576 pixfmt:yuyv422
tb:1/1000000 fr:25/1 sar:0/1 sws_param:flags=2
[format @ 0x28e3520] compat: called with args=[yuv422p]
[format @ 0x28e3520] Setting 'pix_fmts' to value 'yuv422p'
[auto-inserted scaler 0 @ 0x28d9c20] Setting 'flags' to value '0x4'
[auto-inserted scaler 0 @ 0x28d9c20] w:iw h:ih flags:'0x4' interl:0
[format @ 0x28e3520] auto-inserting filter 'auto-inserted scaler 0'
between the filter 'Parsed_null_0' and the filter 'format'
[AVFilterGraph @ 0x28d9a40] query_formats: 4 queried, 2 merged, 1
already done, 0 delayed
[auto-inserted scaler 0 @ 0x28d9c20] w:720 h:576 fmt:yuyv422 sar:0/1 ->
w:720 h:576 fmt:yuv422p sar:0/1 flags:0x4
[graph 1 input from stream 0:0 @ 0x28e3420] Setting 'time_base' to value
'1/44100'
[graph 1 input from stream 0:0 @ 0x28e3420] Setting 'sample_rate' to
value '44100'
[graph 1 input from stream 0:0 @ 0x28e3420] Setting 'sample_fmt' to
value 's16'
[graph 1 input from stream 0:0 @ 0x28e3420] Setting 'channel_layout' to
value '0x3'
[graph 1 input from stream 0:0 @ 0x28e3420] tb:1/44100 samplefmt:s16
samplerate:44100 chlayout:0x3
[audio format for output stream 0:1 @ 0x28e39c0] Setting 'sample_fmts'
to value 's16'
[AVFilterGraph @ 0x28e3c80] query_formats: 4 queried, 9 merged, 0
already done, 0 delayed
Output #0, matroska, to '/Store3/Test/t_20150801_1735.mkv':
  Metadata:
    encoder         : Lavf56.40.101
    Stream #0:0, 0, 1/1000: Video: ffv1, 1 reference frame (FFV1 /
0x31564646), yuv422p, 720x576, 1/25, q=2-31, 200 kb/s, 25 fps, 1k tbn,
25 tbc
    Metadata:
      encoder         : Lavc56.49.101 ffv1
    Stream #0:1, 0, 1/1000: Audio: pcm_s16le ([1][0][0][0] / 0x0001),
44100 Hz, stereo, s16, 1411 kb/s
    Metadata:
      encoder         : Lavc56.49.101 pcm_s16le
Stream mapping:
  Stream #1:0 -> #0:0 (rawvideo (native) -> ffv1 (native))
  Stream #0:0 -> #0:1 (pcm_s16le (native) -> pcm_s16le (native))
Press [q] to stop, [?] for help
Cliping frame in rate conversion by 0.000008
Cliping frame in rate conversion by 0.001564
[matroska @ 0x2912aa0] Writing block at offset 819, size 256709, pts 0,
dts 0, duration 40, keyframe 1
[matroska @ 0x2912aa0] Writing block at offset 257536, size 65472, pts
0, dts 0, duration 371, keyframe 1
[matroska @ 0x2912aa0] Writing block at offset 323016, size 203784, pts
40, dts 40, duration 40, keyframe 0
Cliping frame in rate conversion by 0.000023
[matroska @ 0x2912aa0] Writing block at offset 526808, size 197800, pts
80, dts 80, duration 40, keyframe 0
Cliping frame in rate conversion by 0.000099
[matroska @ 0x2912aa0] Writing block at offset 724616, size 197400, pts
120, dts 120, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002419
[matroska @ 0x2912aa0] Writing block at offset 922024, size 197169, pts
160, dts 160, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002495
[matroska @ 0x2912aa0] Writing block at offset 1119201, size 197045, pts
200, dts 200, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002541
[matroska @ 0x2912aa0] Writing block at offset 1316254, size 196771, pts
240, dts 240, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002647
[matroska @ 0x2912aa0] Writing block at offset 1513033, size 196840, pts
280, dts 280, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002861
[matroska @ 0x2912aa0] Writing block at offset 1709881, size 196501, pts
320, dts 320, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002861
[matroska @ 0x2912aa0] Writing block at offset 1906390, size 196874, pts
360, dts 360, duration 40, keyframe 0
Cliping frame in rate conversion by 0.002937
[matroska @ 0x2912aa0] Writing block at offset 2103272, size 46372, pts
371, dts 371, duration 263, keyframe 1
[matroska @ 0x2912aa0] Writing block at offset 2149652, size 196698, pts
400, dts 400, duration 40, keyframe 0
Cliping frame in rate conversion by 0.003197
[matroska @ 0x2912aa0] Writing block at offset 2346358, size 196898, pts
440, dts 440, duration 40, keyframe 0
Cliping frame in rate conversion by 0.001198
[matroska @ 0x2912aa0] Starting new cluster at offset 2543264 bytes, pts
480dts 480
[matroska @ 0x2912aa0] Writing block at offset 2543280, size 198783, pts
480, dts 480, duration 40, keyframe 1
Cliping frame in rate conversion by 0.001564me=00:00:01.00
bitrate=21827.4kbits/s
[matroska @ 0x2912aa0] Writing block at offset 2742071, size 196317, pts
520, dts 520, duration 40, keyframe 0
Cliping frame in rate conversion by 0.003517
[matroska @ 0x2912aa0] Writing block at offset 2938396, size 196642, pts
560, dts 560, duration 40, keyframe 0
Cliping frame in rate conversion by 0.003670
[matroska @ 0x2912aa0] Writing block at offset 3135046, size 196711, pts
600, dts 600, duration 40, keyframe 0
Cliping frame in rate conversion by 0.001991
[matroska @ 0x2912aa0] Writing block at offset 3331765, size 65472, pts
634, dts 634, duration 371, keyframe 1
[matroska @ 0x2912aa0] Writing block at offset 3397245, size 196497, pts
640, dts 640, duration 40, keyframe 0
Cliping frame in rate conversion by 0.003685
[matroska @ 0x2912aa0] Writing block at offset 3593750, size 196305, pts
680, dts 680, duration 40, keyframe 0
Cliping frame in rate conversion by 0.003990
[matroska @ 0x2912aa0] Writing block at offset 3790063, size 19