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• Live Audio Streaming with live555

  19 août 2014, par Godspped

  I am trying to send a MP2 encoded frame via RTSP (live555) from a live source, (microphone). I am using ffmpeg to encode audio stream, and I am sending it overriding FramedSource and for the OnDemandServer I am using MPEG1or2AudioRTPSink.hh and MPEG1or2AudioStreamFramer.hh.

  Now in VLC I get to hear maybe half a second worth of sound and then it just stops... I dont know what I am doing wrong.

  Has anyone experienced this problem before ? Am I doing this right, should I be override a different class ?

  Thanks in advance.

• ffmpeg video merging issues for videos recorded from andriod mobile phone

  14 avril 2021, par Nishit Modi

  Following is the command I'm using :

  


  sudo ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex "[1]tpad=start_mode=clone:start_duration=15[tr];[0][tr]xstack=inputs=2:layout=0_0|w0_0[v];[1:a]adelay=15s:all=true[a1];[0:a][a1]amix=inputs=2[a]" -map "[v]" -map "[a]" output.mp4


  


  It took a couple of hours to merge the videos. Original videos are 6 MBs in size. Merged video is approx 2 GB in size.

  


  It is working fine with videos recorded from the iphone.

  


  Update :
The issue is regarding different fps in different videos. If two videos are of different fps, then it is taking too long and eventually break.

  


  Full log :

  


  ffmpeg -i video1.mp4 -i video2.mp4 -filter_complex "[1]tpad=start_mode=clone:start_duration=15[tr];[0][tr]xstack=inputs=2:layout=0_0|w0_0[v];[1:a]adelay=15s:all=true[a1];[0:a][a1]amix=inputs=2[a]" -map "[v]" -map "[a]" output_ia_2.mp4
    ffmpeg version 4.3.2-0york0~16.04 Copyright (c) 2000-2021 the FFmpeg developers
      built with gcc 5.4.0 (Ubuntu 5.4.0-6ubuntu1~16.04.12) 20160609
      configuration: --prefix=/usr --extra-version='0york0~16.04' --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librabbitmq --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libsrt --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libzimg --enable-pocketsphinx --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
      libavutil      56. 51.100 / 56. 51.100
      libavcodec     58. 91.100 / 58. 91.100
      libavformat    58. 45.100 / 58. 45.100
      libavdevice    58. 10.100 / 58. 10.100
      libavfilter     7. 85.100 /  7. 85.100
      libavresample   4.  0.  0 /  4.  0.  0
      libswscale      5.  7.100 /  5.  7.100
      libswresample   3.  7.100 /  3.  7.100
      libpostproc    55.  7.100 / 55.  7.100
    Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '97FD4344-23C3-4668-AA40-E5E724338352-3149-0000018389D9630F.mp4':
      Metadata:
        major_brand     : qt  
        minor_version   : 0
        compatible_brands: qt  
        creation_time   : 2021-04-09T00:43:28.000000Z
      Duration: 00:00:15.03, start: 0.000000, bitrate: 10342 kb/s
        Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 226 kb/s (default)
        Metadata:
          creation_time   : 2021-04-09T00:43:28.000000Z
          handler_name    : Core Media Audio
        Stream #0:1(und): Video: h264 (Main) (avc1 / 0x31637661), yuvj420p(pc, bt709), 720x1280, 10111 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default)
        Metadata:
          creation_time   : 2021-04-09T00:43:28.000000Z
          handler_name    : Core Media Video
          encoder         : H.264
    Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'android_ritesh.mp4':
      Metadata:
        major_brand     : mp42
        minor_version   : 0
        compatible_brands: isommp42
        creation_time   : 2021-04-13T06:39:16.000000Z
        com.android.version: 10
      Duration: 00:00:09.59, start: 0.000000, bitrate: 5288 kb/s
        Stream #1:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, unknown/bt470bg/unknown), 720x1280, 5152 kb/s, SAR 1:1 DAR 9:16, 17.31 fps, 59.94 tbr, 90k tbn, 180k tbc (default)
        Metadata:
          creation_time   : 2021-04-13T06:39:16.000000Z
          handler_name    : VideoHandle
        Stream #1:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 131 kb/s (default)
        Metadata:
          creation_time   : 2021-04-13T06:39:16.000000Z
          handler_name    : SoundHandle
    Stream mapping:
      Stream #0:0 (aac) -> amix:input0
      Stream #0:1 (h264) -> xstack:input0
      Stream #1:0 (h264) -> tpad
      Stream #1:1 (aac) -> adelay
      xstack -> Stream #0:0 (libx264)
      amix -> Stream #0:1 (aac)
    Press [q] to stop, [?] for help
    [swscaler @ 0x5628692bd340] deprecated pixel format used, make sure you did set range correctly
    [mp4 @ 0x562868aa7dc0] Frame rate very high for a muxer not efficiently supporting it.
    Please consider specifying a lower framerate, a different muxer or -vsync 2
    [libx264 @ 0x562868af2400] MB rate (648000000) > level limit (16711680)
    [libx264 @ 0x562868af2400] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX FMA3 BMI2 AVX2
    [libx264 @ 0x562868af2400] profile High, level 6.2
    [libx264 @ 0x562868af2400] 264 - core 155 r2917 0a84d98 - H.264/MPEG-4 AVC codec - Copyleft 2003-2018 - 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=6 lookahead_threads=1 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 'output_ia_2.mp4':
      Metadata:
        major_brand     : qt  
        minor_version   : 0
        compatible_brands: qt  
        encoder         : Lavf58.45.100
        Stream #0:0: Video: h264 (libx264) (avc1 / 0x31637661), yuvj420p(pc, progressive), 1440x1280, q=-1--1, 90k tbn, 90k tbc (default)
        Metadata:
          encoder         : Lavc58.91.100 libx264
        Side data:
          cpb: bitrate max/min/avg: 0/0/0 buffer size: 0 vbv_delay: N/A
        Stream #0:1: Audio: aac (LC) (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 69 kb/s (default)
        Metadata:
          encoder         : Lavc58.91.100 aac
    More than 1000 frames duplicated      0kB time=00:00:00.00 bitrate=N/A speed=   0x    
More than 10000 frames duplicated   4352kB time=00:00:00.09 bitrate=358592.3kbits/s dup=8991 drop=0 speed=0.00141x    
frame=15000 fps=131 q=33.0 size=    7680kB time=00:00:00.16 bitrate=378802.6kbits/s dup=14985 drop=0 speed=0.00145x 


  


• How to get video start time with libvlc

  7 juillet 2015, par 0xbaadf00d

  I’m trying to sync multiple videos based on the real time they were saved at.

  For playing the video, I ended up with libvlc, but now i’m unable to read the metadata that contains the time at which the video starts.

  I would use the start time to calculate offsets for videos, so that i can sync them with each other.

  I created the video from an rtsp stream with the ffmpeg command

  ffmpeg -i <stream path="path"> -timestamp now output.mp4
  
  </stream>

  looking at the file with ffprobe, I can see that it contains the correct timestamp in creation_time.

  But this I am unable to read with libvlc.

  Is there a way to save the real wallclock start time on the video in such a way that i can read it from libvlc ?

  Other suggestions that tell me how to sync two videos are welcome as well.