Encode video with alpha channel

[xxlray]

I have a sequence of images with transparency which I want to convert into a video with alpha channel. The following attempts did not work:

ffmpeg -f image2 -pattern_type glob -i '*.png' -vcodec png chromakeyed.mov

ffmpeg -f image2 -pattern_type glob -i '*.png' -vcodec vp6a chromakeyed.flv

ffmpeg -f image2 -pattern_type glob -i '*.png' -vcodec huffyuv chromakeyed.avi

ffmpeg -f image2 -pattern_type glob -i '*.png' -vcodec ffvhuv chromakeyed.avi

ffmpeg -f image2 -pattern_type glob -i '*.png' -vcodec qtrle chromakeyed.mov

All returned:

[image2 @ 0x1cb68c0] Could not find codec parameters for stream 0 (Video: png): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
*.png: could not find codec parameters

The files are named "Fire0000.png" counting up.

I furthermore tried

ffmpeg -f image2 -i Fire%04d.png -vcodec png chromakeyed.mov

and

ffmpeg -f image2 -i Fire%04d.png -s 720x480 -vcodec png chromakeyed.mov

Both return

[image2 @ 0x1cb68c0] Could not find codec parameters for stream 0 (Video: png): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Fire%04d.png: could not find codec parameters

The message "*.png: could not find codec parameters" only comes with ffmpeg 2.0.1. "glob -i '*.png'" worked with version N-53430-g2c2e69b from May 25 2013 05:26:47 but the results were crappy.

[lukeiamyourfather]

For starters I'd go with Libav. What are you trying to do with the videos? Some codecs are better than others depending on who/what needs to be able to decode the videos.

[xxlray]

For starters I'd go with Libav.

Is this just a guess or do you know it will work?

What are you trying to do with the videos?

It's a muzzle blast (gun fire) effect which I need to join to a video file for re-using it in one of my films. I know that this works in principle as I have another effect which has such an alpha channel.

Some codecs are better than others depending on who/what needs to be able to decode the videos.

As you can see I already tried different codecs. From the error message I guess that the error is in the file selection.

[FakeOutdoorsman]

Please provide a sample input PNG file.

[xxlray]

I'll attach some. These are the first frames from the CC BY licensed video "Machine_Gun_Muzzle_Flash_Final.mov" by footagecrate.com . I extracted them via avidemux and added the alpha channel in gimp.

[FakeOutdoorsman]

ffmpeg -i Fire%04d.png -codec:v qtrle output.mov

or

ffmpeg -pattern_type glob -i '*.png' -codec:v qtrle output.mov

Should both work with recent ffmpeg (not the old, buggy, fake "ffmpeg" from the repo). You can follow a step-by-step guide to compile ffmpeg or simply download and use a Linux build of ffmpeg.

I recommend stream copying the PNG images into a MOV container:

ffmpeg -i Fire%04d.png -codec:v copy output.mov

If your other software does not accept that then try qtrle as shown in the first two commands.

Also see How to create an uncompressed AVI from a series of 1000's of PNG images using FFmpeg.

[xxlray]

ffmpeg -i Fire%04d.png -codec:v qtrle output.mov

Result with ffmpeg 2.0.1 is:

[image2 @ 0x2be5840] Could not find codec parameters for stream 0 (Video: png): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Fire%04d.png: could not find codec parameters

The result with ffmpeg N-53430-g2c2e69b looks crappy (see attachment).

Similar results for

ffmpeg -pattern_type glob -i '*.png' -codec:v qtrle output.mov

not the old, buggy, fake "ffmpeg" from the repo

I downloaded the source and compiled it myself

You can follow a step-by-step guide to compile ffmpeg or simply download and use a Linux build of ffmpeg.
...
Also see How to create an uncompressed AVI from a series of 1000's of PNG images using FFmpeg.

Thanks for the advice but in principle I know how to do it (and did multiple times before). It's "just" this particular one which does not work.

[FakeOutdoorsman]

Result with ffmpeg 2.0.1 is:

[image2 @ 0x2be5840] Could not find codec parameters for stream 0 (Video: png): unspecified size
Consider increasing the value for the 'analyzeduration' and 'probesize' options
Fire%04d.png: could not find codec parameters

Are the attached images from your earlier post all of the input images? I would need each of your input images to attempt to duplicate the issue.

The result with ffmpeg N-53430-g2c2e69b looks crappy (see attachment).

According to which player(s)? It does not look great in ffplay, but it looks better in an After Effects composition, so it may still be usable in your other software.

[xxlray]

Are the attached images from your earlier post all of the input images? I would need each of your input images to attempt to duplicate the issue.

I will attach all (and have to devide them into multiple posts to overcome forum limitations).

According to which player(s)? It does not look great in ffplay

It looks bad in VLC and is not even playable in avidemux (screen stays green). I use openshot for cutting my videos and the effect's background is white instead of transparent (covering the rest of the scene). Here is a comparison how I see it:

comparisson.jpg

[xxlray]

Here is the rest and thanks for your efford.