FFMPEG Output allows invalid format/codec combinations #44468

New Issue

Joerg Mueller · 2015-04-21T16:08:00+02:00

Joerg Mueller commented

2015-04-21 16:08:00 +02:00

System Information
Operating system and graphics card: any

Blender Version
Broken: all

Short description of error
Any video file format combination with video and audio codecs can be selected, but not all work.

Exact steps for others to reproduce the error
The encoding UI panel when selecting a Movie File Format allows different Formats (Flash, Matroska, Ogg, ...), Codecs (PNG, Theora, H.264, DV, ...) and Audio Codecs (PCM, FLAC, Vorbis, MP3, ...) to be selected in pretty much any combination. The (video) Codec is only hidden for Formats that only support one single Codec.

The same is true for the Python API, any combination of values for ffmpeg.format, ffmpeg.codec and ffmpeg.audio_codec can be set (ffmpeg = context.scene.render.ffmpeg).

One failing combination for example is setting H264 as Format and FLAC as Audio Codec. Another example is Quicktime as Format and Theora as Codec.

The problem is that FFMPEG has no API that tells us whether a specific combination works and encoding doesn't fail either. It outputs a file that simply cannot be played back (trying with VLC for example). So the big question is how to deal with this problem? Leave it up to the users to figure out possible combinations? Hardcode possible combinations in the UI or lower at RNA level so that Python API users are also "protected"?

**System Information** Operating system and graphics card: any **Blender Version** Broken: all **Short description of error** Any video file format combination with video and audio codecs can be selected, but not all work. **Exact steps for others to reproduce the error** The encoding UI panel when selecting a Movie File Format allows different Formats (Flash, Matroska, Ogg, ...), Codecs (PNG, Theora, H.264, DV, ...) and Audio Codecs (PCM, FLAC, Vorbis, MP3, ...) to be selected in pretty much any combination. The (video) Codec is only hidden for Formats that only support one single Codec. The same is true for the Python API, any combination of values for ffmpeg.format, ffmpeg.codec and ffmpeg.audio_codec can be set (ffmpeg = context.scene.render.ffmpeg). One failing combination for example is setting H264 as Format and FLAC as Audio Codec. Another example is Quicktime as Format and Theora as Codec. The problem is that FFMPEG has no API that tells us whether a specific combination works and encoding doesn't fail either. It outputs a file that simply cannot be played back (trying with VLC for example). So the big question is how to deal with this problem? Leave it up to the users to figure out possible combinations? Hardcode possible combinations in the UI or lower at RNA level so that Python API users are also "protected"?

Joerg Mueller commented

2015-04-21 16:08:00 +02:00

Changed status to: 'Open'

Joerg Mueller commented

2015-04-21 16:08:00 +02:00

Added subscriber: @neXyon

Sergey Sharybin commented

2015-04-22 17:58:20 +02:00

Changed status from 'Open' to: 'Archived'

Sergey Sharybin closed this issue

2015-04-22 17:58:20 +02:00

Sergey Sharybin self-assigned this 2015-04-22 17:58:20 +02:00

Sergey Sharybin commented

2015-04-22 17:58:20 +02:00

I consider this is up to users to make sure settings are correct. Additionally, if the setting combination is not supported by FFmpeg, it is to be reported to FFmpeg so it throws a proper error.

Disabling anything in the UI in this case is not going to work apart from being a major PITA to maintain. Sure we can try disabling combinations which are not supported by FFmpeg (which we already kind of doing by reporting error message from FFmpeg, laving decision about what's supported and what's not up to FFmpeg itself). but at the same time not all the players supports all combinations which FFmpeg does which means artists are still to be aware of what are they doing.

So thanks for the report, but currently it's just FFmpeg which needs to provide proper error message if something is not supported.

I consider this is up to users to make sure settings are correct. Additionally, if the setting combination is not supported by FFmpeg, it is to be reported to FFmpeg so it throws a proper error. Disabling anything in the UI in this case is not going to work apart from being a major PITA to maintain. Sure we can try disabling combinations which are not supported by FFmpeg (which we already kind of doing by reporting error message from FFmpeg, laving decision about what's supported and what's not up to FFmpeg itself). but at the same time not all the players supports all combinations which FFmpeg does which means artists are still to be aware of what are they doing. So thanks for the report, but currently it's just FFmpeg which needs to provide proper error message if something is not supported.

Joerg Mueller commented

2015-04-23 10:26:40 +02:00

Added subscriber: @ideasman42