使用 ffmpeg 从 mp4 或 flv 中提取 h264 原始视频流生成无效流 [英] extracting h264 raw video stream from mp4 or flv with ffmpeg generate an invalid stream
问题描述
我正在尝试使用 ffmpeg 从 mp4 或 flv h264 视频(youtube 视频)中提取视频流.原来的视频(test.flv)用 ffplay 播放没有问题，ffprobe 报错如下:
I'm trying to extract the video stream from an mp4 or flv h264 video (youtube video) using ffmpeg. The original video (test.flv) play without trouble with ffplay , ffprobe gives an error as follow:
ffprobe version N-55515-gbbbd959 Copyright (c) 2007-2013 the FFmpeg developers
built on Aug 13 2013 18:06:32 with gcc 4.7.3 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av
isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgsm --enable-libilbc --enable-libmodplug --enable-libmp3lame --ena
ble-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-l
ibopus --enable-librtmp --enable-libschroedinger --enable-libsoxr --enable-libsp
eex --enable-libtheora --enable-libtwolame --enable-libvo-aacenc --enable-libvo-
amrwbenc --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libxavs --
enable-libxvid --enable-zlib
libavutil 52. 42.100 / 52. 42.100
libavcodec 55. 27.100 / 55. 27.100
libavformat 55. 13.102 / 55. 13.102
libavdevice 55. 3.100 / 55. 3.100
libavfilter 3. 82.100 / 3. 82.100
libswscale 2. 4.100 / 2. 4.100
libswresample 0. 17.103 / 0. 17.103
libpostproc 52. 3.100 / 52. 3.100
[flv @ 000000000031ea80] Stream discovered after head already parsed
Input #0, flv, from 'test.flv':
Metadata:
starttime : 0
totalduration : 142
totaldatarate : 692
bytelength : 12286492
canseekontime : true
sourcedata : B42B95507HH1381414522145462
purl :
pmsg :
Duration: 00:02:22.02, start: 0.000000, bitrate: 692 kb/s
Stream #0:0: Video: h264 (Main), yuv420p, 640x268, 568 kb/s, 23.98 tbr, 1k t
bn, 47.95 tbc
Stream #0:1: Audio: aac, 44100 Hz, stereo, fltp, 131 kb/s
Stream #0:2: Data: none
Unsupported codec with id 0 for input stream 2
为了摆脱多余的流(我只需要视频)，我使用了以下 ffmpeg 命令行:
to get rid of the extra streams ( I only needs the video) I used the following ffmpeg command line:
ffmpeg -i test.flv -map 0:0 -vcodec copy -an -f h264 test.h264
包括 ffplay 在内的任何播放器都无法读取新流，并在 ffprobe 中出现错误:test.h264:处理 inputq=0B f=0/0 时发现无效数据
The new stream is unreadable by any player including ffplay and gives an error with ffprobe : test.h264: Invalid data found when processing inputq= 0B f=0/0
有人知道我做错了什么吗?
Any body have an idea about what am I doing wrong?
我也尝试过更简单的 youtube 命令行:
I also tried simpler youtube command line:
ffmpeg -i test.flv -vcodec copy -an test.h264
如果我使用其他格式(例如 avi):
if I use another format (avi for example):
ffmpeg -i test.flv -vcodec copy -an test.avi
输出视频有效.
如果我对视频进行转码
ffmpeg -i test.flv -an test.h264
输出也有效
有什么建议吗?
推荐答案
要从 MP4 或 FLV 容器中提取原始视频，您应该指定 -bsf:v h264_mp4toannexb 或 -vbfsh264_mp4toannexb 选项.
To extract a raw video from an MP4 or FLV container you should specify the -bsf:v h264_mp4toannexb or -vbfs h264_mp4toannexb option.
ffmpeg -i test.flv -vcodec copy -an -bsf:v h264_mp4toannexb test.h264
没有H264 Annex B/NAL的原始流无法被播放器解码.使用该选项，ffmpeg 对 NAL 单元中的每个 h264 样本执行简单的复用".
The raw stream without H264 Annex B / NAL cannot be decode by player. With that option ffmpeg perform a simple "mux" of each h264 sample in a NAL unit.
这篇关于使用 ffmpeg 从 mp4 或 flv 中提取 h264 原始视频流生成无效流的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！
