FFMPEG不适用于mp4和stdout [英] FFMPEG doesn't work with mp4 and stdout

问题描述

我需要将文本添加到mp4视频中.如果我将结果写入文件，则一切正常，但我想从ffmpeg流中读取数据.

I need to add text to mp4 video. If I write result to file then everything is OK, but I want to read data from ffmpeg stream.

我运行命令:

ffmpeg -i sample.mp4 -filter_complex "drawtext='text=\"Sample Text\"':x=(w-text_w)/2:y=(h-text_h-line_h)/2:fontsize=40:fontcolor=white:fontfile=TimesNewRoman.ttf:enable='between(t,1,5)'"  -f mp4 -

我收到以下错误:

ffmpeg version 2.2.2-tessus Copyright (c) 2000-2014 the FFmpeg developers
  built on May  7 2014 23:17:42 with clang version 3.3 (tags/RELEASE_33/final)
  configuration: --cc=/opt/local/bin/clang-mp-3.3 --prefix=/Users/tessus/data/ext/ffmpeg/sw --as=yasm --extra-version=tessus --disable-shared --enable-static --disable-ffplay --enable-gpl --enable-pthreads --enable-postproc --enable-libmp3lame --enable-libtheora --enable-libvorbis --enable-libx264 --enable-libx265 --enable-libxvid --enable-libspeex --enable-bzlib --enable-zlib --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libxavs --enable-version3 --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvpx --enable-libgsm --enable-libopus --enable-libmodplug --enable-fontconfig --enable-libfreetype --enable-libass --enable-libbluray --enable-filters --disable-indev=qtkit --enable-runtime-cpudetect
  libavutil      52. 66.100 / 52. 66.100
  libavcodec     55. 52.102 / 55. 52.102
  libavformat    55. 33.100 / 55. 33.100
  libavdevice    55. 10.100 / 55. 10.100
  libavfilter     4.  2.100 /  4.  2.100
  libswscale      2.  5.102 /  2.  5.102
  libswresample   0. 18.100 /  0. 18.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'a5732-480x320-clip01-sound.mp4':
  Metadata:
    major_brand     : M4V 
    minor_version   : 1
    compatible_brands: M4V mp42isom
creation_time   : 2014-02-12 02:23:02
  Duration: 00:00:15.10, start: 0.000000, bitrate: 509 kb/s
Stream #0:0(eng): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv), 480x320 [SAR 1:1 DAR 3:2], 457 kb/s, 29.97 fps, 29.97 tbr, 30k tbn, 59.94 tbc (default)
Metadata:
  creation_time   : 2014-02-12 02:23:02
  handler_name    : Mainconcept MP4 Video Media Handler
Stream #0:1(eng): Audio: aac (mp4a / 0x6134706D), 32000 Hz, stereo, fltp, 46 kb/s (default)
Metadata:
  creation_time   : 2014-02-12 02:23:02
  handler_name    : Mainconcept MP4 Sound Media Handler
[libx264 @ 0x10400d800] using SAR=1/1
[libx264 @ 0x10400d800] using cpu capabilities: MMX2 SSE2Fast SSSE3 SSE4.2 AVX
[libx264 @ 0x10400d800] profile High, level 2.1
[libx264 @ 0x10400d800] 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
[mp4 @ 0x10400d200] muxer does not support non seekable output
Output #0, mp4, to 'pipe:':
  Metadata:
major_brand     : M4V 
minor_version   : 1
compatible_brands: M4V mp42isom
encoder         : Lavf55.33.100
Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 480x320 [SAR 1:1 DAR 3:2], q=-1--1, 90k tbn, 29.97 tbc (default)
Stream #0:1(eng): Audio: aac (libvo_aacenc) ([64][0][0][0] / 0x0040), 32000 Hz, stereo, s16, 128 kb/s (default)
Metadata:
  creation_time   : 2014-02-12 02:23:02
  handler_name    : Mainconcept MP4 Sound Media Handler
Stream mapping:
  Stream #0:0 (h264) -> drawtext (graph 0)
  drawtext (graph 0) -> Stream #0:0 (libx264)
  Stream #0:1 -> #0:1 (aac -> libvo_aacenc)
Could not write header for output file #0 (incorrect codec parameters ?): Invalid argument
Conversion failed!

问题似乎与mp4有关，并且"muxer不支持不可搜索的输出"

It seems the problem is related to mp4 and "muxer does not support non seekable output"

有没有一种解决方案，如何在我们拥有数据的情况下即时添加此类文本并返回视频，而不要等到所有文件都处理完之后.

Is there a solution how to make such text adding on the fly and return video as we have data and not to wait until all file is processed.

谢谢

推荐答案

您不能将MP4与STDOUT一起使用.MP4容器要求编码器在完成从头到尾的写入后，返回并对文件的开头进行更改.由于STDOUT无法搜索，因此STDOUT无法在MP4容器中输出媒体.

You can't use MP4 with STDOUT. The MP4 container requires the encoder to go back and make changes to the beginning of the file after it is done writing through the end. Since STDOUT cannot seek, outputting media in an MP4 container is not possible with STDOUT.

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