ffmpeg usage to encode a video to H264 codec forma

2020-05-14 03:31发布

问题:

I have a *.mp4 video file(MPEG4 video codec) and I am trying to convert this to a H264 video codec format(raw h.264 format) using ffmpeg on Linux(Version - FFmpeg version SVN-r0.5.1-4:0.5.1-1ubuntu1, Copyright (c) 2000-2009 Fabrice Bellard,) using command line as shown below,

ffmpeg -i input .mp4 output.h264 

but I get an error saying -

Unsupported codec for output stream #0.0

Then when i try this option:

ffmpeg -i input .mp4 -formats h264 output.h264 

it still does not work, and gives -

Seems stream 0 codec frame rate differs from container frame rate: 59.94 (5994/100) -> 29.97 (30000/1001)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Rapture.mp4':
  Duration: 00:02:06.44, start: 0.000000, bitrate: 26574 kb/s
    Stream #0.0(eng): Video: h264, yuv420p, 1920x1080, 29.97 tbr, 29.97 tbn, 59.94 tbc
    Stream #0.1(eng): Audio: aac, 48000 Hz, stereo, s16

And then it prints out help on the formats which we get when we do ffmpeg -formats

When I checked the help, ffmpeg -formats, I see below information related to H264 file format and codec:

File format : 

DE h264            raw H.264 video format

Codecs:

D V D  h264         H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10

My questions :

  1. How can I convert the video to a H264 encoded video (raw H264 video format)

  2. When I do ffmpeg -formats, I see many acronyms for the codecs supported, I see many acronyms before the codec name/type such as - D V D S E A, what do they stand for?

  3. How to use the ffmpeg options -vcodec and -formats?

回答1:

I believe you have libx264 installed and configured with ffmpeg to convert video to h264... Then you can try with -vcodec libx264... The -format option is for showing available formats, this is not a conversion option I think...



回答2:

I used these options to convert to the H.264/AAC .mp4 format for HTML5 playback (I think it may help other guys with this problem in some way):

ffmpeg -i input.flv -vcodec mpeg4 -acodec aac output.mp4

UPDATE

As @LordNeckbeard mentioned, the previous line will produce MPEG-4 Part 2 (back in 2012 that worked somehow, I don't remember/understand why). Use the libx264 encoder to produce the proper video with H.264/AAC. To test the output file you can just drag it to a browser window and it should playback just fine.

ffmpeg -i input.flv -vcodec libx264 -acodec aac output.mp4



回答3:

I believe that by now the above answers are outdated (or at least unclear) so here's my little go at it. I tried compiling ffmpeg with the option --enable-encoders=libx264 and it will give no error but it won't enable anything (I can't seem to find where I found that suggestion).

Anyways step-by-step, first you must compile libx264 yourself because repository version is outdated:

  wget ftp://ftp.videolan.org/pub/x264/snapshots/last_x264.tar.bz2
  tar --bzip2 -xvf last_x264.tar.bz2
  cd x264-snapshot-XXXXXXXX-XXXX/
  ./configure
  make
  sudo make install

And then get and compile ffmpeg with libx264 enabled. I'm using the latest release which is "Happiness":

wget http://ffmpeg.org/releases/ffmpeg-0.11.2.tar.bz2
tar --bzip2 -xvf ffmpeg-0.11.2.tar.bz2
cd ffmpeg-0.11.2/
./configure --enable-libx264 --enable-gpl
make
sudo install

Now finally you have the libx264 codec to encode, to check it you may run

ffmpeg -codecs | grep h264

and you'll see the options you have were the first D means decoding and the first E means encoding



回答4:

"C:\Program Files (x86)\ffmpegX86shared\bin\ffmpeg.exe" -y -i "C:\testfile.ts" -an -vcodec libx264 -g 75 -keyint_min 12 -vb 4000k -vprofile high -level 40 -s 1920x1080 -y -threads 0 -r 25 "C:\testfile.h264"

The above worked for me on a Windows machine using a FFmpeg Win32 shared build by Kyle Schwarz. The build was compiled on: Feb 22 2013, at: 01:09:53

Note that -an defines that audio should be skipped.



回答5:

I have a Centos 5 system that I wasn't able to get this working on. So I built a new Fedora 17 system (actually a VM in VMware), and followed the steps at the ffmpeg site to build the latest and greatest ffmpeg.

I took some shortcuts - I skipped all the yum erase commands, added freshrpms according to their instructions:

wget http://ftp.freshrpms.net/pub/freshrpms/fedora/linux/9/freshrpms-release/freshrpms-release-1.1-1.fc.noarch.rpm
rpm -ivh rpmfusion-free-release-stable.noarch.rpm

Then I loaded the stuff that was already readily available:

yum install lame libogg libtheora libvorbis lame-devel libtheora-devel

Afterwards, I only built the following from scratch: libvpx vo-aacenc-0.1.2 x264 yasm-1.2.0 ffmpeg

Then this command encoded with no problems (the audio was already in AAC, so I didn't recode it):

ffmpeg -i input.mov -c:v libx264 -preset slow -crf 22 -c:a copy output.mp4

The result looks just as good as the original to me, and is about 1/4 of the size!



标签: ffmpeg h.264