0

I'm trying to convert a 24fps video to 12fps. While it seems like the conversion is working, ffmpeg is also increasing the duration of the output video (about a second longer). It would seem like the output video should be similar or shorter than the source video.

Here are the commands that I tried:

ffmpeg -i src.mov -r 12 out.mov
ffmpeg -r 24 -i src.mov -r 12 out.mov

And the complete output:

$ ffmpeg -i src.mov -r 12 output.mov
ffmpeg version 2.4.3 Copyright (c) 2000-2014 the FFmpeg developers
  built on Nov  6 2014 23:40:10 with Apple LLVM version 6.0 (clang-600.0.54) (based on LLVM 3.5svn)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/2.4.3 --enable-shared --enable-pthreads --enable-gpl --enable-version3 --enable-nonfree --enable-hardcoded-tables --enable-avresample --enable-vda --cc=clang --host-cflags= --host-ldflags= --enable-libx264 --enable-libfaac --enable-libmp3lame --enable-libxvid
  libavutil      54.  7.100 / 54.  7.100
  libavcodec     56.  1.100 / 56.  1.100
  libavformat    56.  4.101 / 56.  4.101
  libavdevice    56.  0.100 / 56.  0.100
  libavfilter     5.  1.100 /  5.  1.100
  libavresample   2.  1.  0 /  2.  1.  0
  libswscale      3.  0.100 /  3.  0.100
  libswresample   1.  1.100 /  1.  1.100
  libpostproc    53.  0.100 / 53.  0.100
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fc18980da00] multiple edit list entries, a/v desync might occur, patch welcome
    Last message repeated 1 times
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'src.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    encoder         : Lavf54.29.104
    xmp             : <?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
                    : <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.3-c011 66.145661, 2012/02/06-14:56:27        ">
                    :  <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
                    :   <rdf:Description rdf:about=""
                    :     xmlns:xmp="http://ns.adobe.com/xap/1.0/"
                    :     xmlns:xmpDM="http://ns.adobe.com/xmp/1.0/DynamicMedia/"
                    :     xmlns:stDim="http://ns.adobe.com/xap/1.0/sType/Dimensions#"
                    :     xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/"
                    :     xmlns:stEvt="http://ns.adobe.com/xap/1.0/sType/ResourceEvent#"
                    :    xmp:CreateDate="1904-01-01T00:00Z"
                    :    xmp:ModifyDate="2014-12-07T22:15:45Z"
                    :    xmp:MetadataDate="2014-12-07T14:19:26-08:00"
                    :    xmpDM:videoAlphaMode="none"
                    :    xmpDM:audioSampleRate="44100"
                    :    xmpDM:audioSampleType="16Int"
                    :    xmpDM:audioChannelType="Stereo"
                    :    xmpDM:videoFrameRate="24.000000"
                    :    xmpDM:startTimeScale="24"
                    :    xmpDM:startTimeSampleSize="1"
                    :    xmpDM:tapeName=""
                    :    xmpDM:altTapeName=""
                    :    xmpDM:logComment=""
                    :    xmpMM:InstanceID="xmp.iid:0480117407206811822AE6AAF5D55871"
                    :    xmpMM:DocumentID="xmp.did:709C869A082068118083DD6390749A0C"
                    :    xmpMM:OriginalDocumentID="xmp.did:709C869A082068118083DD6390749A0C">
                    :    <xmpDM:videoFrameSize
                    :     stDim:w="1280"
                    :     stDim:h="720"
                    :     stDim:unit="pixel"/>
                    :    <xmpDM:duration
                    :     xmpDM:value="2816"
                    :     xmpDM:scale="1/1000"/>
                    :    <xmpDM:startTimecode
                    :     xmpDM:timeValue="00:00:00:00"
                    :     xmpDM:timeFormat="24Timecode"/>
                    :    <xmpDM:altTimecode
                    :     xmpDM:timeValue="00:00:00:00"
                    :     xmpDM:timeFormat="24Timecode"/>
                    :    <xmpMM:History>
                    :     <rdf:Seq>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:719C869A082068118083DD6390749A0C"
                    :       stEvt:when="2014-12-07T14:08:22-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:729C869A082068118083DD6390749A0C"
                    :       stEvt:when="2014-12-07T14:08:23-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :      <rdf:li
                    :       stEvt:action="modified"
                    :       stEvt:parameters="unknown modifications"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0180117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:15:45-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0280117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:15:46-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0480117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:19:26-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :     </rdf:Seq>
                    :    </xmpMM:History>
                    :   </rdf:Description>
                    :  </rdf:RDF>
                    : </x:xmpmeta>
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    : <?xpacket end="w"?>
  Duration: 00:00:02.82, start: 0.238005, bitrate: 2127 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], 1503 kb/s, 24 fps, 24 tbr, 24 tbn, 48 tbc (default)
    Metadata:
      handler_name    : Apple Alias Data Handler
    Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 44100 Hz, stereo, fltp, 191 kb/s (default)
    Metadata:
      handler_name    : Apple Alias Data Handler
[libx264 @ 0x7fc189829a00] using SAR=1/1
[libx264 @ 0x7fc189829a00] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX AVX2 FMA3 LZCNT BMI2
[libx264 @ 0x7fc189829a00] profile High, level 3.1
[libx264 @ 0x7fc189829a00] 264 - core 142 r2455 021c0dc - 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=12 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, mov, to 'output.mov':
  Metadata:
    major_brand     : qt
    minor_version   : 512
    compatible_brands: qt
    xmp             : <?xpacket begin="" id="W5M0MpCehiHzreSzNTczkc9d"?>
                    : <x:xmpmeta xmlns:x="adobe:ns:meta/" x:xmptk="Adobe XMP Core 5.3-c011 66.145661, 2012/02/06-14:56:27        ">
                    :  <rdf:RDF xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">
                    :   <rdf:Description rdf:about=""
                    :     xmlns:xmp="http://ns.adobe.com/xap/1.0/"
                    :     xmlns:xmpDM="http://ns.adobe.com/xmp/1.0/DynamicMedia/"
                    :     xmlns:stDim="http://ns.adobe.com/xap/1.0/sType/Dimensions#"
                    :     xmlns:xmpMM="http://ns.adobe.com/xap/1.0/mm/"
                    :     xmlns:stEvt="http://ns.adobe.com/xap/1.0/sType/ResourceEvent#"
                    :    xmp:CreateDate="1904-01-01T00:00Z"
                    :    xmp:ModifyDate="2014-12-07T22:15:45Z"
                    :    xmp:MetadataDate="2014-12-07T14:19:26-08:00"
                    :    xmpDM:videoAlphaMode="none"
                    :    xmpDM:audioSampleRate="44100"
                    :    xmpDM:audioSampleType="16Int"
                    :    xmpDM:audioChannelType="Stereo"
                    :    xmpDM:videoFrameRate="24.000000"
                    :    xmpDM:startTimeScale="24"
                    :    xmpDM:startTimeSampleSize="1"
                    :    xmpDM:tapeName=""
                    :    xmpDM:altTapeName=""
                    :    xmpDM:logComment=""
                    :    xmpMM:InstanceID="xmp.iid:0480117407206811822AE6AAF5D55871"
                    :    xmpMM:DocumentID="xmp.did:709C869A082068118083DD6390749A0C"
                    :    xmpMM:OriginalDocumentID="xmp.did:709C869A082068118083DD6390749A0C">
                    :    <xmpDM:videoFrameSize
                    :     stDim:w="1280"
                    :     stDim:h="720"
                    :     stDim:unit="pixel"/>
                    :    <xmpDM:duration
                    :     xmpDM:value="2816"
                    :     xmpDM:scale="1/1000"/>
                    :    <xmpDM:startTimecode
                    :     xmpDM:timeValue="00:00:00:00"
                    :     xmpDM:timeFormat="24Timecode"/>
                    :    <xmpDM:altTimecode
                    :     xmpDM:timeValue="00:00:00:00"
                    :     xmpDM:timeFormat="24Timecode"/>
                    :    <xmpMM:History>
                    :     <rdf:Seq>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:719C869A082068118083DD6390749A0C"
                    :       stEvt:when="2014-12-07T14:08:22-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:729C869A082068118083DD6390749A0C"
                    :       stEvt:when="2014-12-07T14:08:23-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :      <rdf:li
                    :       stEvt:action="modified"
                    :       stEvt:parameters="unknown modifications"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0180117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:15:45-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0280117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:15:46-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :      <rdf:li
                    :       stEvt:action="saved"
                    :       stEvt:instanceID="xmp.iid:0480117407206811822AE6AAF5D55871"
                    :       stEvt:when="2014-12-07T14:19:26-08:00"
                    :       stEvt:softwareAgent="Adobe Premiere Pro CS6 (Macintosh)"
                    :       stEvt:changed="/metadata"/>
                    :     </rdf:Seq>
                    :    </xmpMM:History>
                    :   </rdf:Description>
                    :  </rdf:RDF>
                    : </x:xmpmeta>
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    :
                    : <?xpacket end="w"?>
    encoder         : Lavf56.4.101
    Stream #0:0(eng): Video: h264 (libx264) (avc1 / 0x31637661), yuv420p, 1280x720 [SAR 1:1 DAR 16:9], q=-1--1, 12 fps, 12288 tbn, 12 tbc (default)
    Metadata:
      handler_name    : Apple Alias Data Handler
      encoder         : Lavc56.1.100 libx264
    Stream #0:1(eng): Audio: aac (libfaac) (mp4a / 0x6134706D), 44100 Hz, stereo, s16, 128 kb/s (default)
    Metadata:
      handler_name    : Apple Alias Data Handler
      encoder         : Lavc56.1.100 libfaac
Stream mapping:
  Stream #0:0 -> #0:0 (h264 (native) -> h264 (libx264))
  Stream #0:1 -> #0:1 (aac (native) -> aac (libfaac))
Press [q] to stop, [?] for help
frame=   45 fps=0.0 q=-1.0 Lsize=     504kB time=00:00:03.58 bitrate=1153.1kbits/s dup=1 drop=39
video:496kB audio:1kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: 1.351465%
[libx264 @ 0x7fc189829a00] frame I:1     Avg QP:16.16  size: 19137
[libx264 @ 0x7fc189829a00] frame P:42    Avg QP:19.07  size: 11474
[libx264 @ 0x7fc189829a00] frame B:2     Avg QP:19.62  size:  3256
[libx264 @ 0x7fc189829a00] consecutive B-frames: 91.1%  8.9%  0.0%  0.0%
[libx264 @ 0x7fc189829a00] mb I  I16..4: 39.3% 57.6%  3.1%
[libx264 @ 0x7fc189829a00] mb P  I16..4: 10.8% 22.4%  0.4%  P16..4: 36.1%  6.9%  2.4%  0.0%  0.0%    skip:20.9%
[libx264 @ 0x7fc189829a00] mb B  I16..4:  0.7%  2.1%  0.0%  B16..8: 25.5%  2.5%  0.3%  direct: 3.2%  skip:65.8%  L0:59.6% L1:36.8% BI: 3.6%
[libx264 @ 0x7fc189829a00] 8x8 transform intra:66.0% inter:89.9%
[libx264 @ 0x7fc189829a00] coded y,uvDC,uvAC intra: 30.7% 68.7% 5.3% inter: 12.0% 39.0% 0.2%
[libx264 @ 0x7fc189829a00] i16 v,h,dc,p: 33% 27% 18% 22%
[libx264 @ 0x7fc189829a00] i8 v,h,dc,ddl,ddr,vr,hd,vl,hu: 34% 25% 28%  2%  2%  2%  2%  2%  2%
[libx264 @ 0x7fc189829a00] i4 v,h,dc,ddl,ddr,vr,hd,vl,hu: 38% 23% 12%  4%  6%  6%  5%  4%  3%
[libx264 @ 0x7fc189829a00] i8c dc,h,v,p: 42% 25% 30%  4%
[libx264 @ 0x7fc189829a00] Weighted P-Frames: Y:7.1% UV:2.4%
[libx264 @ 0x7fc189829a00] ref P L0: 74.8%  5.4% 14.9%  4.7%  0.2%
[libx264 @ 0x7fc189829a00] ref B L0: 90.9%  9.1%
[libx264 @ 0x7fc189829a00] kb/s:1082.75
2
  • Thanks. What does ffmpeg say the duration is for the output file? ffmpeg -i output.mov You can omit the xmp metadata.
    – llogan
    Dec 7, 2014 at 23:52
  • @LordNeckbeard Duration: 00:00:03.75, start: 0.023220, bitrate: 1101 kb/s
    – Guest
    Dec 7, 2014 at 23:56

1 Answer 1

0

I used avconv instead, which got much closer to what I wanted:

avconv -r 24 -i src.mov -an -vf fps=fps=12 output.mov
1
  • 2
    Now your command is different. Did you also test ffmpeg with -vf fps=12?
    – llogan
    Dec 8, 2014 at 2:48

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