php - 将 avi 转换为 mp4 后的 ffmpeg 需要等到视频在 Flash 播放器中加载 100% 否则视频正在缓冲

Question

因此，如果现在解决了我的 ffmpeg 旅程的所有问题，我只需要在转换视频后立即在 Flash 播放器中播放，而无需等到视频 100% 加载我使用:

if ($success_msg) {
    $tmp_parts = explode('.', $file['name']);
    $ext = array_pop($tmp_parts);
    $ext = strtolower($ext);
    if($ext == "avi" && $convert_avi == true) {
        $convert_source = _VIDEOS_DIR_PATH.$new_name;
        $conv_name = substr(md5($file['name'].rand(1,888)), 2, 10).".mp4";
        $converted_file  = _VIDEOS_DIR_PATH.$conv_name;
        $ffmpeg_command = 'ffmpeg -i '.$convert_source.' -acodec libfaac -vcodec libx264 -s 1280x720 -ar 44100 -async 44100 -r 29.970 -ac 2 -qscale 5 '.$converted_file;
        echo exec($ffmpeg_command);
        $sql = "UPDATE pm_temp SET url = '".$conv_name."' WHERE url = '".$new_name."' LIMIT 1";
        $result = @mysql_query($sql);
        unlink($convert_source);
    }
    echo $success_msg;
}

转换视频

编辑#1 ffmpeg concole 输出与快速启动功能:

root@1tb:~# ffmpeg -i sample.avi -movflags faststart -acodec libfaac -vcodec libx264 -s 1280x720 -ar 44100 -async 44100 -r 29.970 -ac 2 -qscale 5 consample.mp4
ffmpeg version 0.7.15, Copyright (c) 2000-2013 the FFmpeg developers
  built on Feb 22 2013 07:18:58 with gcc 4.4.5
  configuration: --enable-libdc1394 --prefix=/usr --extra-cflags='-Wall -g ' --cc='ccache cc' --enable-shared --enable-libmp3lame --enable-gpl --enable-libvorbis --enable-pthreads --enable-libfaac --enable-libxvid --enable-postproc --enable-x11grab --enable-libgsm --enable-libtheora --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libx264 --enable-libspeex --enable-nonfree --disable-stripping --enable-avfilter --enable-libdirac --disable-decoder=libdirac --enable-libfreetype --enable-libschroedinger --disable-encoder=libschroedinger --enable-version3 --enable-libopenjpeg --enable-libvpx --enable-librtmp --extra-libs=-lgcrypt --disable-altivec --disable-armv5te --disable-armv6 --disable-vis
  libavutil    50. 43. 0 / 50. 43. 0
  libavcodec   52.123. 0 / 52.123. 0
  libavformat  52.111. 0 / 52.111. 0
  libavdevice  52.  5. 0 / 52.  5. 0
  libavfilter   1. 80. 0 /  1. 80. 0
  libswscale    0. 14. 1 /  0. 14. 1
  libpostproc  51.  2. 0 / 51.  2. 0
[mp3 @ 0x15389100] Header missing
[mpeg4 @ 0x15386dc0] Invalid and inefficient vfw-avi packed B frames detected
Input #0, avi, from 'sample.avi':
  Metadata:
    encoder         : VirtualDubMod 1.5.10.2 (build 2540/release)
  Duration: 00:01:01.81, start: 0.000000, bitrate: 1194 kb/s
    Stream #0.0: Video: mpeg4, yuv420p, 640x352 [PAR 1:1 DAR 20:11], 23.98 tbr, 23.98 tbn, 23.98 tbc
    Stream #0.1: Audio: mp3, 48000 Hz, stereo, s16, 128 kb/s
[MOV/3GP/MP4/3G2 muxer @ 0x15386c80] [Eval @ 0x7ffffec71230] Undefined constant or missing '(' in 'faststart'
[MOV/3GP/MP4/3G2 muxer @ 0x15386c80] Unable to parse option value "faststart"
Invalid value 'movflags' for option 'faststart'

Answer 1

您必须使用 -movflags faststart 以避免播放器必须缓冲整个视频。

通常，mp4 的内部索引将被写入文件的末尾(因为在处理文件时它不知道/不完整)。 faststart一旦完成，将执行另一个 muxer pass 将该索引移动到前面，以便播放器可以在不先读取整个文件的情况下读取它。

确保您的 ffmpeg 版本足够新以支持此功能。

例子:

# -strict 2 just for allowing the aac encoder. 
$ ffmpeg -i in.mkv -strict -2 -movflags faststart out.mp4
ffmpeg version 57577-g83b8d74 Copyright (c) 2000-2013 the FFmpeg developers
  built on Oct 28 2013 15:31:30 with Apple LLVM version 4.2 (clang-425.0.28) (based on LLVM 3.2svn)
Input #0, matroska,webm, from 'in.mkv':
  Duration: 00:00:23.02, start: 0.000000, bitrate: 4128 kb/s
    Stream #0:0: Video: h264 (High), yuv420p, 1280x716 [SAR 1:1 DAR 320:179], 25 fps, 25 tbr, 1k tbn, 50 tbc (default)
    Stream #0:1: Audio: mp3, 44100 Hz, stereo, s16p, 192 kb/s (default)
...
Output #0, mp4, to 'out.mp4':
  Metadata:
    encoder         : Lavf55.19.104
    Stream #0:0: Video: h264 (libx264) ([33][0][0][0] / 0x0021), yuv420p, 1280x716 [SAR 1:1 DAR 320:179], q=-1--1, 12800 tbn, 25 tbc (default)
    Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, stereo, fltp, 128 kb/s (default)
Stream mapping:
  Stream #0:0 -> #0:0 (h264 -> libx264)
  Stream #0:1 -> #0:1 (mp3 -> aac)
Press [q] to stop, [?] for help
...   
[mp4 @ 0x7f9c44016e00] Starting second pass: moving the moov atom to the beginning of the file
...
video:5426kB audio:361kB subtitle:0 global headers:0kB muxing overhead 0.291754%
...

由于您的 ffmpeg 很旧，因此使用 qt-faststart 可能会更好。而不是 ffmpeg 本身。有一个 tools/qt-faststart.c在 ffmpeg 中，从 0.5(或其他)开始，您可以编译 cc -o qt-faststart tools/qt-faststart.c并使用 ./qt-faststart in.mp4 out.mp4 .