ffmpeg mp4 to wmv and wmv to mp4

//大小=》变小
ffmpeg -i 1.mp4 -b:v 2M -vcodec msmpeg4 -acodec wmav2 1_mp4.wmv
//大小=》变大
ffmpeg -i 1.mp4 -qscale 2 -vcodec msmpeg4 -acodec wmav2 2_mp4.wmv

ffmpeg -i 1.mp4 -q:a 2 -q:v 2 -vcodec msmpeg4 -acodec wmav2 3_mp4.wmv

ffmpeg -i 1.mp4 outputfile.wmv

ffmpeg -i 1.MP4 -c:v wmv2 -b:v 20M -c:a wmav2 -b:a 192k output.wmv

ffmpeg -i input.wmv -c:v libx264 -crf 23 -profile:v high -r 30 -c:a libfaac -q:a 100 -ar 48000 output.mp4

ffmpeg -i input.wmv -c:v libx264 -crf 23 -c:a libfaac -q:a 100 output.mp4

How to get better quality converting MP4 to WMV with ffmpeg?

up vote6down votefavorite

5

I am converting MP4 files to WMV with these two rescaling commands:

ffmpeg -i test.mp4 -y -vf scale=-1:360 test1.wmv
ffmpeg -i test.mp4 -y -vf scale=-1:720 test2.wmv

I've also tried:

ffmpeg -g 1 -b 16000k -i test1.mp4 test1.wmv

However, the .wmv files that are produced are "blocky and grainy" as you can see here in a small section of a video screenshot:

These are the sizes:

test.mp4 - 106 MB
test1.wmv - 6 MB
test2.wmv - 16 MB

How can I increase the quality/size of the resulting .wmv files (the size of the .wmv files is of no concern)?

ffmpeg mp4 wmv

shareimprove this question

asked Jun 18 '12 at 8:53 Edward Tanguay 60.2k224572875

add a comment

3 Answers

activeoldestvotes

up vote10down vote

You can simply use the -sameq parameter ("use same quantizer as source") which produces a much larger sized video file (227 MB) but with excellent quality.

ffmpeg -sameq -i test.mp4 -y -vf scale=-1:360 test1.wmv

shareimprove this answer

answered Jun 18 '12 at 9:23 Edward Tanguay 60.2k224572875

7

A better solution is to use -qscale (or -qscale:v or -q:v depending on your syntax preference); generally with a value of 2-5. A lower value is higher quality, and 2 can be considered "visually lossless". -sameq is not designed to be used between formats that do not share the same quantizer scale, and this may be the case for you. – LordNeckbeard Jun 18 '12 at 16:03

2

Also you're applying -sameq as an input option (anything before -i). Probably works as expected, but keep in mind not all options applied to the input will be applied to the output. – LordNeckbeard Jun 18 '12 at 16:07

-sameq has been removed. When you try to use it ffmpeg offers "use -qscale 0 or an equivalent quality factor option", and it errors out with an invalid argument. – Robert Koernke Jan 6 at 17:04

add a comment

 

up vote3down vote

One thing I discovered after many frustrating attempts of enhancing the final quality was that if you don't specify a bitrate, it'll use a quite low average. Try -b 1000k for a starting point, and experiment increasing or decreasing it until you reach the desired result. Your file will be quite bigger or smaller, accordingly.

shareimprove this answer

edited Feb 26 '13 at 22:07

answered Feb 7 '13 at 22:59 Fabio Ceconello 11.2k42645

add a comment

up vote2down vote

Consider the following command instead (some outdated commands in the final answer section):

ffmpeg -i test.mp4 -c:v wmv2 -b:v 1024k -c:a wmav2 -b:a 192k test1.wmv

REFERENCES

• List item http://askubuntu.com/questions/352920/fastest-way-to-convert-videos-batch-or-single

shareimprove this answer

edited Jan 18 at 10:26

answered Jan 18 at 10:02 Reinhard Behrens 212

add a comment

http://stackoverflow.com/questions/11079577/how-to-get-better-quality-converting-mp4-to-wmv-with-ffmpeg