“UbuntuHelp:AndroidVideoEncoding”的版本间的差异

2010年5月19日 (三) 17:24的最新版本

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https://help.ubuntu.com/community/AndroidVideoEncoding

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Encoding Video for the Android Phone, for example, HTC/Google G1

HTC/Google G1 phone can decode mpeg4, h263 and h264 codecs and can play mp4 and 3gp video formats. Since these format combinations are relatively uncommon, here are instructions to convert your videos to the compatible format. If your source is a DVD, skip to [[UbuntuHelp:[Using HandBrake (GUI)|HandBrake section]]]

Using Avidemux (GUI)

Supported operations

Instructions

This method has been tested in Ubuntu 9.04, adapted from this article. It will produce a movie encoded with mpeg4 codec, fast but not optimal.

1. Install the avidemux package from the Ubuntu multiverse repository
2. Configure video options:
   1. Click on the video dropdown on the left and select MPEG-4 ASP (lavc)
   2. Click Configure->Encoding Mode->Single Pass - Bitrate
   3. Enter in any bitrate up to 512 to be safe, then click Ok.
   4. Click Filters->MPlayer Resize->Double Click on it-> Width:432, Height:320 if source video is standard resolution.
      1. For widescreen source, choose Width:480, Height:272.
      2. Click Ok, then close.
3. Configure audio options:
   1. Click Audio->AAC (FAAC)
   2. Configure->Bitrate 96
   3. Click Format->MP4
4. Click Save and specify a name.mp4 for your video, encoding will start
5. Once enconding has completed, plug in your phone via USB and transfer the video to it, anywhere. The videos can be opened directly using a file manager such as Astro.

Using WinFF (GUI)

This method will achieve superior compression using a newer video codec and higher level of control. 模板:Http://winff.org/images/screenshots/winff044-ubuntu-small.jpg

Supported operations

Install WinFF on Ubuntu 9.04 or later using by clicking on the following link: apt:winff. For older version of Ubuntu, please click on the link for the instructions: Instructions for WinFF installation

Instructions

• Click on Options and verify that Additional Options are selected -- they will show up on the bottom of the screen
• Click on Add and select one or multiple movies that you want to convert.
• Select Convert to: Ipod
• Select Device Presets: H.264 for Ipod *Linux* (4:3) for standard resolution or H.264 for Ipod *Linux* (16:9) for wide resolution
• In the Additional Options below, choose Video Settings and type Video Size: 432 x 320 for standard resolution and 480 x 272 for wide resolution
• In Audio Settings: If you are planning to listen primarily with headphones, do nothing. If you are planning to listen on the speakerphone, select Audio Channels: 1 to create mono sound.
• Click on Convert toolbar icon.

Using HandBrake (GUI)

模板:Http://trac.handbrake.fr/raw-attachment/wiki/LinGuiScreenshots/HandBrake-Pic.jpeg

Supported operations

Installation

Summary of instructions from [1]. Ubuntu 9.10 karmic and later: add ppa:handbrake-ubuntu/ppa to your system's Software Sources. Ubuntu 9.04 and earlier: Copy and paste the following command into the terminal to add the new WinFF repository (example for JAUNTY, SUBSTITUTE WITH YOUR VERSION):

echo "For 9.04 and earlier versions only!"
sudo apt-key adv --recv-keys --keyserver keyserver.ubuntu.com A58BCAE3
echo "deb http://ppa.launchpad.net/handbrake-ubuntu/ppa/ubuntu jaunty main" | sudo tee /etc/apt/sources.list.d/handbrake.list
sudo apt-get update && sudo apt-get install handbrake-gtk

G1-specific Video Conversion Instructions

1. When encoding a DVD, select File, "/dev/dvd". Name might be different.
2. When encoding a file, click on Source and select a desired source file.
3. Click on Preset: Apple -> iPhone & iPod Touch
4. Click on Video tab. In Quality, reduce quality to 49 and uncheck Constant Rate Factor
5. Click on Start.
6. Once encoding has completed, plug in your phone via USB and transfer the video to it, anywhere. The videos can be opened directly using a file manager such as Astro.

Preset File for Import

Tested on HTC Hero: To import, choose "options" at the bottom right of the window, then import. attachment:Android_Tested_on_Hero.plist

Expert mode: Using ffmpeg (command line)

Supported operations

Introduction

This method will give you the greatest control of the resulting output. For most versions of Ubuntu, ffmpeg in Medibuntu contains this "unlocked" ffmpeg. Enable Medibuntu with the instructions here.

MPEG4 (standard) encoding

The default encoding of the videos is MPEG-4 ASP (i.e. "xvid") format video using ffmpeg's mpeg4 encoder. If you are interested in higher quality encodings, which will take quite a bit more time but may result in better quality, see H.264 section below. To convert a file source-video.avi to a desired G1 format, run the following command:

ffmpeg -i source-video.avi -s 480x320 -vcodec mpeg4 -acodec aac -ac 1 -ar 16000 -r 13 -ab 32000 -aspect 3:2 output-video.G1.mp4

This is VERY basic. For full options, go to FFmpeg Documentation

• -s is "size" of output video.
• -vcodec Choices for G1 are mpeg4 and h263. IMHO I get better quality and marginally smaller file size with mpeg4.
• -acodec aac is the audio codec. I know of no other choice here for this purpose.
• Older versions of ffmpeg called this option -acodec libfaac.
• -ac 1 Number of audio channels. Use 1 to save filesize since you only have one speaker. Unless you like wearing those painful earbuds all the time. Then use -ac 2.
• -ar 16000 Audio sampling rate in Hertz. Some formats won't work with anything other than 8kHz. 16 kHz seems okay to me, considering what I'm watching it on. Don't expect !HiFi from a phone.
• -r 13 Frames per second. Larger is smoother, but 30 fps requires double the file size of 15 fps. 12 is about the slowest my eyes can comfortably watch. Since DVDs are right at 25 FPS, 12.5 being half of this, I go with 13. My camera makes 30 FPS; in that case, use -r 15.
• -ab 32000 bitrate of the audio -- 32 kbps in this case. Normally I'd balk at such low numbers, but remember, I'm trying to keep filesize low. I'm not broadcasting to a large audience with this, am I? No, it's for me. For you? Use your best judgement. Experiment a little.
• -aspect 3:2 Obviously, this is the aspect ratio of the output file. I'm not sure it matters, when the output size is being set before.

While ffmpeg is running, you should see the following:

Output #0, mp4, to 'terminal.G1.mp4':
   Stream #0.0: Video: mpeg4, yuv420p, 480x320 [PAR 1:1 DAR 3:2], q=2-31, 200 kb/s, 13.00 tb(c)
   Stream #0.1: Audio: aac, 16000 Hz, mono, s16, 32 kb/s

Very old versions of Android Video Player incorrectly scaled video, that is, if the video size was anything but 480 by 320, you would see stretching in the playback on the G1. It is no longer a problem.

H.264 Encoding

H.264 (MPEG-4 AVC) is a newer codec that the G1 supports. It's able to deliver similar quality at half the bitrate of MPEG-4 ASP! However, it is an extremely slow and CPU-intensive encoder. Expect the encode to take 5x longer than mpeg4 or xvid. You also need ffmpeg with x264 support. Due to the G1's limited feature support for H.264, the command for doing the encode is that much more complex. If you are interested in technical details, G1 supports only the Constrained Baseline Profile (CBP) dialect of H.264; videos that use more advanced features of H.264 play incorrectly, or not at all. In case of incorrect video encoding, the most typical error is a black screen during playback on G1 while the audio plays. Note that since we are striving for better quality, the audio encoding is also set to higher standards. Assuming source movie has aspect ratio 4:3, the command is:

ffmpeg -i source-video.avi -s 432x320 -b 384k -vcodec h264 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -subq 7 -trellis 1 -refs 5 -bf 0 -flags2 +mixed_refs -coder 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -acodec aac output-video.G1.mp4

Some versions of ffmpeg use older syntax, that is, -vcodec libx264 and -acodec libfaac. For example of a typical American camcoder which records at 640x480 resolution with 30 frames per second rate, we will resize image and change the rate (-r 15):

ffmpeg -i myparty.avi -s 432x320 -b 384k -vcodec h264 -flags +loop+mv4 -cmp 256 -partitions +parti4x4+parti8x8+partp4x4+partp8x8+partb8x8 -subq 7 -trellis 1 -refs 5 -bf 0 -flags2 +mixed_refs -coder 0 -me_range 16 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -qmin 10 -qmax 51 -qdiff 4 -acodec aac -r 15  myparty.G1.mp4

While ffmpeg is running, you should see the following:

Output #0, mp4, to 'myparty.G1.mp4':
  Stream #0.0: Video: h264, yuv420p, 432x320, q=10-51, 384 kb/s, 15.00 fps(c)
  Stream #0.1: Audio: aac, 44100 Hz, stereo, 64 kb/s

Expert mode: Using mencoder (command line)

Supported operations

Introduction

These instructions are only applicable to encoding DVD tracks into G1 compatible video format. This is not a preferred method due to its complexity. Please read a chapter about H.264 above in the FFmpeg description.

Installation

Upgrade to the latest version of software using the following PPA repositories: |MPlayer and MEncoder and |SMPlayer (Optional) a very handy GUI front-end for MPlayer. Additionally, install gpac package from universe repository.

Conversion

The following command a track number 10 into an AVI file. As mentioned previously, the source has aspect ratio of 4:3, so we choose 432x320 as output most appropriate for G1 screen.

mencoder dvd://10 -dvd-device /dev/dvd -aid 128 -o output.avi -ovc x264 -x264encopts bitrate=640:nocabac:direct_pred=auto:me=umh:frameref=2:level_idc=21:partitions=all:subq=6:threads=auto:trellis=1:vbv_maxrate=768:vbv_bufsize=244:bframes=0 -oac faac -faacopts br=96:mpeg=4:object=2 -channels 1 -srate 48000 -vf scale=432:320,harddup

Warning: Currently, mencoder is not able to produce MP4 containers usable by mobiles players. Do not use the following mencoder option: -of lavf -lavfopts format=mp4. After that, convert AVI to MP4 containers using these instructions. Alternatively, use MP4Box utility from gpac package which strictly complies to MPEG4 standard.

MP4Box -aviraw video output.avi 
MP4Box -aviraw audio output.avi
mv output_audio.raw output_audio.aac
MP4Box -add output_video.h264 -add output_audio.aac output.mp4
rm output.avi

Plug-in your phone via USB and copy output.mp4 to your Android mobile device.

Get help

As always, Ubuntuforums is a great place to ask for help. Please use the Multimedia Production category.

Primary source

• http://androidcommunity.com/forums/showthread.php?p=88879#post88879 - Initial post that details the procedure.
• http://h264.code-shop.com/trac/wiki/Encoding - Settings for H.264 codec.
• Video converter is the easiest way to get your video in the format you want, convert video and audio to iPod, PSP, iPhone, Zune, Xbox.
• Pavtube video converter supports to convert video between different video formats.

Inspired by

• iPodVideoEncoding
• Compare prices on best ipod video converter for deals on more Electronics products.

Additional information

• FFmpeg documentation
• Unlocking Some Secrets of the Android G1 Video Capabilities
• Encoding videos for G1
• Powerful,versatile video file converter which convert video file between all popular video formats.
• Extensive discussion of sizing videos for G1. Excel spreadsheet for calculations is attached.