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• Merge videos with different Frame Rates using MP4Parser

  30 juillet 2017, par BorisB

  I am currently successful at using MP4Parser library (https://github.com/sannies/mp4parser) to merge two videos created by my phones camera with same frame rates and resolutions. However when I try to merge one I encode via Android MediaCodec with the same resolution and same codec to the one recorded via the phones camera it produces an unplayable file with no errors.

  The only difference between the two files that I can see is the Camera file has frame rates of this :

  Frame rate mode : Variable
  Frame rate : 29.970 (29970/1000) FPS
  Minimum frame rate : 29.831 FPS
  Maximum frame rate : 30.030 FPS

  and the one I generate via Media Codec has this :

  Frame rate mode : Constant
  Frame rate : 30.000 FPS

  MP4 parser documentation says :
  ’It is important to emphasize that you cannot append any two tracks with : Different resolutions or Different frame-rates’

  So yeah I guess I’m out of luck with that solution.

  Now the only two others solutions I have come across are FFMPEG (which I don’t want to bother with because of licensing issues) and using Mediacodec to first decoded and then encode the video files together.

  Is using Mediacodec basically the most sound approach here ? Will there be problems when I need to add audio into the mix later on ? Most importantly does anyone have a good examples of doing this type of merge ?

  I know http://bigflake.com/mediacodec/ is the best source for these types of examples but I can’t really see anything there that does exactly this. Any help would be greatly appreciated.

• Segment duration variation is higher than the +/- 50% allowed by DASH-IF

  23 mars 2016, par timhysniu

  I am implement a proof of concept page with video player that uses DASH. I am having a difficult time getting the video right and I am not sure whether this is an encoding issue or MP4Box issue.

  Since I am working on Ubuntu I had to change a few parameters for ffmpeg, but according to what I read this should be fine :

  ~/ffmpeg/ffmpeg -c:a aac -ar 44100 -ac 1 -codec:v libx264 \
  
    -profile:v baseline -level 13 -b:v 2000k video_transcoded.mp4 -i video.mp4

  Then to create the MPD I am running this :

  MP4Box -dash 10000 -dash-profile live \
  
    -segment-name video_transcoded video_transcoded.mp4

  I am getting this response at the end, which might be why no player will play my video :

    [DASH] two languages in adaptation set: und will be kept eng will be ignored
  
    DASHing file video_transcoded.mp4
  
    [DASH]: Segment duration variation is higher than the  50% allowed by DASH-IF (min 1.044, max 10.448) - please reconsider encoding

  Here is the output of ffmpeg :

      ffmpeg version N-53477-g689211d-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2016 the FFmpeg developers
  
        built with gcc 5.3.1 (Debian 5.3.1-10) 20160224
  
        configuration: --enable-gpl --enable-version3 --disable-shared --disable-debug --enable-runtime-cpudetect --enable-libmp3lame --enable-libx264 --enable-libx265 --enable-libwebp --enable-libspeex --enable-libvorbis --enable-libvpx --enable-libfreetype --enable-fontconfig --enable-libxvid --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libtheora --enable-libvo-amrwbenc --enable-gray --enable-libopenjpeg --enable-libopus --enable-libass --enable-gnutls --enable-libvidstab --enable-libsoxr --enable-frei0r --enable-libfribidi --disable-indev=sndio --disable-outdev=sndio --enable-librtmp --enable-libmfx --cc=gcc
  
        libavutil      55. 19.100 / 55. 19.100
  
        libavcodec     57. 28.100 / 57. 28.100
  
        libavformat    57. 28.100 / 57. 28.100
  
        libavdevice    57.  0.101 / 57.  0.101
  
        libavfilter     6. 39.102 /  6. 39.102
  
        libswscale      4.  0.100 /  4.  0.100
  
        libswresample   2.  0.101 /  2.  0.101
  
        libpostproc    54.  0.100 / 54.  0.100
  
      Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'gladiator.mp4':
  
        Metadata:
  
          major_brand     : isom
  
          minor_version   : 1
  
          compatible_brands: isomavc1
  
          creation_time   : 2013-02-12 19:14:56
  
        Duration: 02:50:56.98, start: 0.000000, bitrate: 923 kb/s
  
          Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x544 [SAR 1:1 DAR 40:17], 823 kb/s, 23.98 fps, 23.98 tbr, 24k tbn, 47.95 tbc (default)
  
          Metadata:
  
            creation_time   : 2013-02-12 19:14:56
  
            handler_name    : 2000.Extended.Remastered.720p.BluRay.x264-HDEVO.mkv.264#trackID=1:fps=23.976@GPAC0.5.1-DEV-rev4283
  
          Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 95 kb/s (default)
  
          Metadata:
  
            creation_time   : 2013-02-12 15:32:26
  
            handler_name    : Sound Media Handler
  
      [libx264 @ 0xaf12920] using SAR=1/1
  
      [libx264 @ 0xaf12920] frame MB size (80x34) > level limit (396)
  
      [libx264 @ 0xaf12920] DPB size (3 frames, 8160 mbs) > level limit (0 frames, 2376 mbs)
  
      [libx264 @ 0xaf12920] MB rate (65214) > level limit (11880)
  
      [libx264 @ 0xaf12920] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
  
      [libx264 @ 0xaf12920] profile Constrained Baseline, level 1.3
  
      [libx264 @ 0xaf12920] 264 - core 148 r236 a01e339 - H.264/MPEG-4 AVC codec - Copyleft 2003-2016 - http://www.videolan.org/x264.html - options: cabac=0 ref=3 deblock=1:0:0 analyse=0x1:0x111 me=hex subme=7 psy=1 psy_rd=1.00:0.00 mixed_ref=1 me_range=16 chroma_me=1 trellis=1 8x8dct=0 cqm=0 deadzone=21,11 fast_pskip=1 chroma_qp_offset=-2 threads=1 lookahead_threads=1 sliced_threads=0 nr=0 decimate=1 interlaced=0 bluray_compat=0 constrained_intra=0 bframes=0 weightp=0 keyint=250 keyint_min=23 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=2000 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
  
      Output #0, mp4, to 'gladiator2.mp4':
  
        Metadata:
  
          major_brand     : isom
  
          minor_version   : 1
  
          compatible_brands: isomavc1
  
          encoder         : Lavf57.28.100
  
          Stream #0:0(und): Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x544 [SAR 1:1 DAR 40:17], q=-1--1, 2000 kb/s, 23.98 fps, 24k tbn, 23.98 tbc (default)
  
          Metadata:
  
            creation_time   : 2013-02-12 19:14:56
  
            handler_name    : 2000.Extended.Remastered.720p.BluRay.x264-HDEVO.mkv.264#trackID=1:fps=23.976@GPAC0.5.1-DEV-rev4283
  
            encoder         : Lavc57.28.100 libx264
  
          Side data:
  
            cpb: bitrate max/min/avg: 0/0/2000000 buffer size: 0 vbv_delay: -1
  
          Stream #0:1(eng): Audio: aac (LC) ([64][0][0][0] / 0x0040), 44100 Hz, mono, fltp, 69 kb/s (default)
  
          Metadata:
  
            creation_time   : 2013-02-12 15:32:26
  
            handler_name    : Sound Media Handler
  
            encoder         : Lavc57.28.100 aac
  
      Stream mapping:
  
        Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  
        Stream #0:1 -> #0:1 (aac (native) -> aac (native))
  
      Press [q] to stop, [?] for help

  After transcoding is completed I get this :

  frame=  132 fps= 15 q=25.0 Lsize=    1112kB time=00:00:05.31 bitrate=1713.0kbits/s speed=0.603x    
  
  video:1062kB audio:45kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 0.414602%
  
  [libx264 @ 0xab63de0] frame I:1     Avg QP:21.29  size:121187
  
  [libx264 @ 0xab63de0] frame P:131   Avg QP:23.40  size:  7372
  
  [libx264 @ 0xab63de0] mb I  I16..4:  9.2%  0.0% 90.8%
  
  [libx264 @ 0xab63de0] mb P  I16..4:  0.9%  0.0%  0.3%  P16..4: 37.2%  7.0%  1.8%  0.0%  0.0%    skip:52.7%
  
  [libx264 @ 0xab63de0] final ratefactor: 21.58
  
  [libx264 @ 0xab63de0] coded y,uvDC,uvAC intra: 48.8% 72.2% 30.7% inter: 8.9% 14.6% 0.8%
  
  [libx264 @ 0xab63de0] i16 v,h,dc,p: 28% 33% 18% 21%
  
  [libx264 @ 0xab63de0] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 22% 16% 15%  8%  7%  8%  6% 12%  6%
  
  [libx264 @ 0xab63de0] i8c dc,h,v,p: 52% 21% 19%  8%
  
  [libx264 @ 0xab63de0] ref P L0: 92.9%  5.2%  1.8%
  
  [libx264 @ 0xab63de0] kb/s:1646.80
  
  [aac @ 0xab64c40] Qavg: 112.650

  What can I do to make this work ?

• Encode video with changing bit rates using FFmpeg [migrated]

  4 décembre 2012, par Pavan K

  I would like to encode a 30 min video using ffmpeg. I am able to achieve this using

  ffmpeg -i in.mp4 -vcodec libvpx -vb 1024k -keyint_min 150 -g 150 -an out.webm

  But I would like to encode different segments of the video at different rate and not use a constant rate of 1024k. Is this possible ?

  I know what time they have to switch encoding. For example say 5 min of video I want an encoding rate of 1024k and next 5 min I am okay with 250k bitrate. I do not want to use VBR or I don't want to cut the video and encode them at different rates and then join them.

  Is this possible. I read the man page for ffmpeg and saw there were options for

  startime and time 

  But I am not sure how exactly I can do this assuming this to be possible.