diveintomark.org的作者参与的自由软件项目。
http://code.google.com/u/pilgrim/
我关注的是
http://code.google.com/p/podencoder/
This is a small (one file!) script for Linux users who want to encode video for fifth-generation video iPods. Its focus is on high-quality encodes (at the expense of being quite slow on older machines). It can encode one or more tracks from a physical DVD, ripped DVD (VIDEO_TS folder), or a video file in any format readable by mplayer/mencoder.
** 视频中的aspect radio的意思
transcoding是一个可以转换视频编码的自由软件工具。
http://www.transcoding.org/cgi-bin/transcode?Aspect_Ratio
Aspect Ratio
Aspect ratio refers generally to the ratio between the width and height of an object. Aspect ratios are typically written either as a ratio, such as "4:3" or "16:9", or as a decimal number obtained by dividing the first number by the second, such as 1.333 or 1.778. (In many cases, including these two examples, aspect ratios cannot be represented accurately as decimal numbers, so the ratio format is preferred.)
There are two types of aspect ratios involved in video editing. One is display aspect ratio or DAR; this is the ratio most commonly referred to by the term "aspect ratio", and is the ratio of the video frame's physical (displayed) width to its height, regardless of the number of pixels used to represent the video image. Typical DAR values are 4:3 for standard-definition video or 16:9 for widescreen television.
The other type of aspect ratio is pixel aspect ratio, or PAR (also known as "sample aspect ratio" or SAR). This is the ratio of the width to the height of a single pixel in the video image; a PAR of 1:1 means that each pixel is a perfect square, while a PAR of 2:1 would mean that each pixel is a rectangle twice as wide as it is tall. PAR can be used to refer either to the pixels in a video file, or to the pixels on a physical display device such as a television.
These two aspect ratios are related to each other and the number of pixels in the video frame (or display device) as follows:
DAR width
--- = ------
PAR height
When transcoding a video, it is important to take both of these aspect ratios into account. For example, most NTSC DVDs use a video frame size of 720x480 pixels but a DAR of either 4:3 or 16:9, meaning that the PAR is not 1:1. If you transcode that DVD to an AVI file without changing the size, the resulting video may look "squished" in one direction. This is because most video playing software (with the notable exception of MPlayer) assumes that AVI files have a PAR of 1:1, resulting in a DAR of 720:480, or 3:2, for the displayed video frame.
Choosing the proper size for a video when transcoding can be a confusing task. For some examples of how to determine size and aspect ratio, see: Calculating frame size and aspect ratio
ffmpeg -i /temp/MPEGAV/AVSEQ01.DAT -target pal-vcd 2.mpg
我是要重新编辑一下这些文件，所以我转换成dv1394，而且我会批量，所以我用
for f in /media/cdrom1/vcd/*.dat;do ffmpeg -i $f -target dv1394 $f-dv1394
我还是用批量转
for f in /cdrom/*.vob; do tovid -pal -dvd -in $f -out $f-dvd; done
ffmpeg支持很多格式，可以用 ffmpeg -formats 来查看
想快速定位你要找的，比如我想看看dv都有什么表示，用 ffmpeg -formats ｜grep dv 就好了
ffmpeg -i video.flv -ab 56 -ar 22050 -b 500 -s 320x240 test.mpg
参考
http://www.google.com/search?q=ffmpeg+flv+to+mpeg
http://asuaf.org/~jj/blog/index.php/2006/01/08/convert-googl...
http://soenkerohde.com/tutorials/ffmpeg/
方法一：还是用上面的命令，放在for do循环中。我一贯的方法。
for f in *.flv;do ffmepg -i $f -ab 56 -ar 22050 -b 500 -s 320x240 $f.mpg;done
方法二：
http://wiki.rijiben.org/Ziyouruanjian/%e6%89%b9%e9%87%8f%e8%...
#!/bin/bash
echo based on "fakap mp3-to-flv converter
http://blog.fakap.net/mp3toflv/"
echo "Copyright (c) mypapit 2007"
echo more on this script: http://pengyou.rijiben.org
echo Usage: sh flvtompeg.sh *
echo ""
if (($# ==0))
then
echo "Usage: flvtompeg [flv files] ..."
exit
fi
while (($# !=0 ))
do
ffmpeg -i $1 -ab 56 -ar 22050 -b 500 -s 320x240 $1.mpg
shift
done
看看能否成功～
参观基诺山寨那天用俺的DC录的，效果一般，声音尚可。
6M多，不知能否上传成功。
虾米了——
你选中的文件 201.avi 无法作为附件上传，你只能够上传扩展名为 jpg jpeg gif png txt html doc xls pdf ppt pps 的文件。
