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Activity Forums Compression Techniques empty file when converting .flv to .mp4

  • empty file when converting .flv to .mp4

    Posted by Raul Benitez on July 28, 2014 at 8:28 pm

    After upgrading to the newest version of ffmpeg I ran a test convert to see if it was working. The output came out with an empty file. So my script is working but I think I’m missing a step hence the empty file. Take a look at what I did

    CODE: SELECT ALL
    @node1 [/home/ebaitbiz/www/ebait_images/myd13Yv]# ffmpeg -i credit_app_1.flv
    ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
    built on Jul 26 2014 10:29:10 with gcc 4.1.2 (GCC) 20080704 (Red Hat 4.1.2-54)
    configuration: –enable-version3 –enable-libopencore-amrnb –enable-libmp3lame –enable-libx264 –enable-libxvid –enable-gpl –enable-postproc –enable-nonfree
    libavutil 52. 92.101 / 52. 92.101
    libavcodec 55. 69.100 / 55. 69.100
    libavformat 55. 49.100 / 55. 49.100
    libavdevice 55. 13.102 / 55. 13.102
    libavfilter 4. 11.102 / 4. 11.102
    libswscale 2. 6.100 / 2. 6.100
    libswresample 0. 19.100 / 0. 19.100
    libpostproc 52. 3.100 / 52. 3.100
    Input #0, flv, from ‘credit_app_1.flv’:
    Metadata:
    hasKeyframes : true
    hasMetadata : true
    datasize : 2919345
    hasVideo : true
    canSeekToEnd : false
    lasttimestamp : 21
    lastkeyframetimestamp: 21
    audiosize : 96337
    hasAudio : true
    audiodelay : 0
    videosize : 2821526
    metadatacreator : inlet media FLVTool2 v1.0.5 – https://www.inlet-media.de/flvtool2
    hasCuePoints : false
    Duration: 00:00:21.50, start: 0.000000, bitrate: 1088 kb/s
    Stream #0:0: Video: flv1, yuv420p, 640×360, 1075 kb/s, 24 fps, 24 tbr, 1k tbn, 1k tbc
    Stream #0:1: Audio: mp3, 22050 Hz, mono, s16p, 33 kb/s
    At least one output file must be specified

    @node1 [/home/ebaitbiz/www/ebait_images/myd13Yv]# ffmpeg -i credit_app_1.flv -b 1088k -ab 33k credit_app_1_.mp4
    ffmpeg version 2.2.git Copyright (c) 2000-2014 the FFmpeg developers
    built on Jul 26 2014 10:29:10 with gcc 4.1.2 (GCC) 20080704 (Red Hat 4.1.2-54)
    configuration: –enable-version3 –enable-libopencore-amrnb –enable-libmp3lame –enable-libx264 –enable-libxvid –enable-gpl –enable-postproc –enable-nonfree
    libavutil 52. 92.101 / 52. 92.101
    libavcodec 55. 69.100 / 55. 69.100
    libavformat 55. 49.100 / 55. 49.100
    libavdevice 55. 13.102 / 55. 13.102
    libavfilter 4. 11.102 / 4. 11.102
    libswscale 2. 6.100 / 2. 6.100
    libswresample 0. 19.100 / 0. 19.100
    libpostproc 52. 3.100 / 52. 3.100
    Input #0, flv, from ‘credit_app_1.flv’:
    Metadata:
    hasKeyframes : true
    hasMetadata : true
    datasize : 2919345
    hasVideo : true
    canSeekToEnd : false
    lasttimestamp : 21
    lastkeyframetimestamp: 21
    audiosize : 96337
    hasAudio : true
    audiodelay : 0
    videosize : 2821526
    metadatacreator : inlet media FLVTool2 v1.0.5 – https://www.inlet-media.de/flvtool2
    hasCuePoints : false
    Duration: 00:00:21.50, start: 0.000000, bitrate: 1088 kb/s
    Stream #0:0: Video: flv1, yuv420p, 640×360, 1075 kb/s, 24 fps, 24 tbr, 1k tbn, 1k tbc
    Stream #0:1: Audio: mp3, 22050 Hz, mono, s16p, 33 kb/s
    Please use -b:a or -b:v, -b is ambiguous
    [libx264 @ 0x979d4a0] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2
    [libx264 @ 0x979d4a0] profile High, level 3.0
    [libx264 @ 0x979d4a0] 264 – core 142 r2453 ea0ca51 – H.264/MPEG-4 AVC codec – Copyleft 2003-2014 – https://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=24 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=24 scenecut=40 intra_refresh=0 rc_lookahead=40 rc=abr mbtree=1 bitrate=1088 ratetol=1.0 qcomp=0.60 qpmin=0 qpmax=69 qpstep=4 ip_ratio=1.40 aq=1:1.00
    [aac @ 0x9804920] The encoder ‘aac’ is experimental but experimental codecs are not enabled, add ‘-strict -2’ if you want to use it.
    [libx264 @ 0x979d4a0] final ratefactor: 21.37

    The result was
    -rw-r–r– 1 ebaitbiz ebaitbiz 2924756 Jul 25 15:47 credit_app_1.flv
    -rw-r–r– 1 root root 0 Jul 28 15:49 credit_app_1_.mp4

    Im sure its something simple I”m missing.

    Thanks!

    Raul Benitez replied 11 years, 9 months ago 2 Members · 2 Replies
  • 2 Replies
  • Jim Sustacek

    July 29, 2014 at 12:49 pm

    Notice the experimental AAC encoder warning? I’d try satisfying that first as described, by adding “-strict -2” to your command:

    ffmpeg -i credit_app_1.flv -b 1088k -ab 33k -strict -2 credit_app_1_.mp4

    Probably also worth heeding the “-b”/”-ab” ambiguous warnings too, and updating those options to “-b:v” and “-b:a” respectively, although it shouldn’t be causing the blank file:

    ffmpeg -i credit_app_1.flv -b:v 1088k -b:a 33k -strict -2 credit_app_1_.mp4

    Also your blank file was created by the “root” user — are you running ffmpeg as root? Normally you should get warnings about overwriting and permission errors, but just to be sure, delete the mp4 file before running the command, and maybe add a “-y” option to your command so it overwrites without prompting too.

  • Raul Benitez

    July 29, 2014 at 2:23 pm

    This actually worked!

    Thank you so much.

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