ffmpeg: Buffer queue overflow error appears when adding audio with amix to overlay filtered video

I am trying to use ffmpeg to combine multiple video files at different start times using the overlay filter.

When I do so without any audio the generated result is correct.

When I add in audio filter elements with amix to include the audio from the various overlayed videos, ffmpeg starts issuing errors of this kind:

[Parsed_overlay_4 @ 0x305ec40] [framesync @ 0x305ed68] Buffer queue overflow, dropping.

Any help in avoiding this, or alternative ways of:

• Combining multiple videos clips
• Setting the start time of each video clip
• Having the audio for each clip play in sync with its corresponding video

would be much appreciated.

I've already tried lots of combinations of setpts/asetpts/amerge/pan and can't get it working.

Here is my ffmpeg command line and output for the case that causes an error (the if clause in the overlay y= is to cause the overlayed clips to scroll across the video while they play):

ffmpeg -y \
 -i /wintmp/vid/butterfly_base.mp4 \
 -i /wintmp/vid/party_overlay.mp4 \
 -i /wintmp/vid/car_overlay.mp4 \
 -pix_fmt yuv420p -r 30000/1001 -filter_complex " [1:v] setpts=PTS-STARTPTS+2/TB [v1] ; [0:v] [v1] overlay=x=50:y='if( gte(t,2), H-(t-2)*128, NAN)' [o1] ; [2:v] setpts=PTS-STARTPTS+3/TB,scale=width=320:height=240 [v2] ; [o1] [v2]  overlay=x=100:y='if( gte(t,3), H-(t-3)*102.4, NAN)' [outv] ; [1:a] adelay=2000|2000 [a1] ; [2:a] adelay=3000|3000 [a2] ; [0:a] [a1] [a2] amix=inputs=3:duration=longest [outa] " -map "[outv]" -map "[outa]" /wintmp/vid/combined.mp4
ffmpeg version N-81978-g03d6d5f Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 4.8 (Ubuntu 4.8.4-2ubuntu1~14.04.3)
  configuration: --enable-gpl --enable-libx264 --enable-nonfree --enable-libfdk-aac
  libavutil      55. 32.100 / 55. 32.100
  libavcodec     57. 61.102 / 57. 61.102
  libavformat    57. 51.107 / 57. 51.107
  libavdevice    57.  0.102 / 57.  0.102
  libavfilter     6. 63.100 /  6. 63.100
  libswscale      4.  1.100 /  4.  1.100
  libswresample   2.  2.100 /  2.  2.100
  libpostproc    54.  0.100 / 54.  0.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/wintmp/vid/butterfly_base.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.48.100
  Duration: 00:00:08.01, start: 0.000000, bitrate: 550 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 480x272 [SAR 1:1 DAR 30:17], 412 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #0:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 127 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from '/wintmp/vid/party_overlay.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    title           : Teenage Fun, 1949 Style - http://www.archive.org/details/CEP503
    date            : 1949
    encoder         : Lavf55.48.100
    comment         : license:  http://creativecommons.org/licenses/publicdomain/
  Duration: 00:00:04.02, start: 0.000000, bitrate: 587 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 320x240 [SAR 1:1 DAR 4:3], 476 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
    Stream #1:1(und): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 101 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from '/wintmp/vid/car_overlay.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.48.100
  Duration: 00:00:05.09, start: 0.000000, bitrate: 951 kb/s
    Stream #2:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 94 kb/s (default)
    Metadata:
      handler_name    : SoundHandler
    Stream #2:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 640x480 [SAR 1:1 DAR 4:3], 854 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
    Metadata:
      handler_name    : VideoHandler
[libx264 @ 0x3066780] using SAR=1/1
[libx264 @ 0x3066780] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI2
[libx264 @ 0x3066780] profile High, level 2.1
[libx264 @ 0x3066780] 264 - core 142 - H.264/MPEG-4 AVC codec - Copyleft 2003-2014 - http://www.videolan.org/x264.html - options: cabac=1 ref=3 deblock=1:0:0 analyse=0x3:0x113 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=1 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=12 lookahead_threads=2 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=3 b_pyramid=2 b_adapt=1 b_bias=0 direct=1 weightb=1 open_gop=0 weightp=2 keyint=250 keyint_min=25 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=crf mbtree=1 crf=23.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
Output #0, mp4, to '/wintmp/vid/combined.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.51.107
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 480x272 [SAR 1:1 DAR 30:17], q=-1--1, 29.97 fps, 30k tbn, 29.97 tbc (default)
    Metadata:
      encoder         : Lavc57.61.102 libx264
    Side data:
      cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: -1
    Stream #0:1: Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s (default)
    Metadata:
      encoder         : Lavc57.61.102 aac
Stream mapping:
  Stream #0:0 (h264) -> overlay:main
  Stream #0:1 (aac) -> amix:input0
  Stream #1:0 (h264) -> setpts
  Stream #1:1 (aac) -> adelay
  Stream #2:0 (aac) -> adelay
  Stream #2:1 (h264) -> setpts
  overlay -> Stream #0:0 (libx264)
  amix -> Stream #0:1 (aac)
Press [q] to stop, [?] for help
[Parsed_overlay_4 @ 0x305ec40] [framesync @ 0x305ed68] Buffer queue overflow, dropping.
    Last message repeated 15 times
frame=  241 fps=0.0 q=-1.0 Lsize=     608kB time=00:00:08.10 bitrate= 614.6kbits/s speed=9.07x    
video:472kB audio:126kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.638017%
[libx264 @ 0x3066780] frame I:1     Avg QP:24.29  size: 24368
[libx264 @ 0x3066780] frame P:117   Avg QP:24.94  size:  3290
[libx264 @ 0x3066780] frame B:123   Avg QP:31.72  size:   599
[libx264 @ 0x3066780] consecutive B-frames:  6.2% 72.2% 14.9%  6.6%
[libx264 @ 0x3066780] mb I  I16..4:  0.0% 39.4% 60.6%
[libx264 @ 0x3066780] mb P  I16..4:  0.1%  1.4%  1.1%  P16..4: 32.1% 19.9% 14.0%  0.0%  0.0%    skip:31.4%
[libx264 @ 0x3066780] mb B  I16..4:  0.0%  0.3%  0.2%  B16..8: 27.4%  4.9%  1.2%  direct: 1.3%  skip:64.7%  L0:35.2% L1:57.1% BI: 7.8%
[libx264 @ 0x3066780] 8x8 transform intra:52.0% inter:52.6%
[libx264 @ 0x3066780] coded y,uvDC,uvAC intra: 89.9% 91.2% 74.9% inter: 15.6% 15.7% 3.1%
[libx264 @ 0x3066780] i16 v,h,dc,p: 29% 33% 11% 27%
[libx264 @ 0x3066780] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 19% 12% 12%  7%  9% 12%  8% 12% 11%
[libx264 @ 0x3066780] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 21% 15% 12%  7% 10% 12%  7% 10%  7%
[libx264 @ 0x3066780] i8c dc,h,v,p: 44% 22% 23% 11%
[libx264 @ 0x3066780] Weighted P-Frames: Y:0.0% UV:0.0%
[libx264 @ 0x3066780] ref P L0: 73.2% 15.2%  7.9%  3.7%
[libx264 @ 0x3066780] ref B L0: 90.6%  9.0%  0.4%
[libx264 @ 0x3066780] ref B L1: 98.2%  1.8%
[libx264 @ 0x3066780] kb/s:480.51
[aac @ 0x3068d40] Qavg: 515.774

Here are the source input videos:

• butterfly_base.mp4 - https://drive.google.com/file/d/0B56RokrDs3xaa2pIR1A4alFyLTg/view?usp=sharing
• party_overlay.mp4 - https://drive.google.com/file/d/0B56RokrDs3xabThYR1lDamtRVm8/view?usp=sharing
• car_overlay.mp4 - https://drive.google.com/file/d/0B56RokrDs3xaUkVXNGdlMzF5a3c/view?usp=sharing

Here is the output video, where you can notice the dropped frames in the overlayed video of the car, where the car in the video stops rotating during playback:

• combined.mp4 - https://drive.google.com/file/d/0B56RokrDs3xaVk1KTzhSZ2c2RVU/view?usp=sharing

If I remove all the audio entirely by running this:

ffmpeg -y \
-i /wintmp/vid/butterfly_base.mp4 \
-i /wintmp/vid/party_overlay.mp4 \
-i /wintmp/vid/car_overlay.mp4 \
-pix_fmt yuv420p -r 30000/1001 -an -filter_complex " [1:v] setpts=PTS-STARTPTS+2/TB [v1] ; [0:v] [v1] overlay=x=50:y='if( gte(t,2), H-(t-2)*128, NAN)' [o1] ; [2:v] setpts=PTS-STARTPTS+3/TB,scale=width=320:height=240 [v2] ; [o1] [v2]  overlay=x=100:y='if( gte(t,3), H-(t-3)*102.4, NAN)' [outv] " -map "[outv]" /wintmp/vid/combined_no_audio.mp4

This no-audio version does not cause any errors and renders the video correctly: https://drive.google.com/file/d/0B56RokrDs3xaTmh0YkpmaGt0aUk/view?usp=sharing

The problem also seems related to the number of overlays. If I just do one overlay the problem does not occur.

Solution 1:

This defect has been reported here before, but is not solved yet.

It's a buffer-related problem and using fifo, afifo filters can help. Try:

ffmpeg -y -i butterfly_base.mp4 -i party_overlay.mp4 -i car_overlay.mp4 -pix_fmt yuv420p -r 30000/1001 -filter_complex " [1:v]fifo, setpts=PTS-STARTPTS+2/TB [v1] ; [0:v]fifo[v0buf];[v0buf][v1] overlay=x=50:y='if( gte(t,2), H-(t-2)*128, NAN)' [o1] ; [2:v]fifo, setpts=PTS-STARTPTS+3/TB,scale=width=320:height=240 [v2] ; [o1] [v2]  overlay=x=100:y='if( gte(t,3), H-(t-3)*102.4, NAN)' [outv] ; [1:a]afifo, adelay=2000|2000 [a1] ; [2:a]afifo, adelay=3000|3000 [a2] ; [0:a]afifo[a0buf];[a0buf] [a1] [a2] amix=inputs=3:duration=longest [outa] " -map "[outv]" -map "[outa]" combined.mp4