adpcm,pcm Encoders/Decoders and possible file extensions with ffmpeg

[alexander121]

Hello,
i would like to ask which file extensions correspond to encoders/decoders whose name starts with adpcm or pcm in FFmpeg ?

Only wav files and pcm files ?

[alexander121]

also do you know what their possible values for the audio quality parameter are (--q:a parameter) ? and which values correspond to high,low,medium quality ?

is there a list with possible quality values for all encoders of FFMPEG ?

[alexander121]

i would like to also ask : is there such a thing as audio containers ? Are containers only for video file formats or for example is it possible
that different audio formats can host many different audio codecs ?

For example does ogg audio format host flac,opus,speex etc audio codecs ?

[pandy]

Specialized or general containers can be used for audio files (specialized container is for example wav when general is for example avi).
Some containers may support limited number of audio codecs - check container for details.

Usually non compressed audio is called RAW (PCM is RAW and can be in fact a completely different extension or no extension at all), compressed audio stream is usually called Elementary Stream and may have unique extension (MP3) or general (RAW) or no extension at all.
Concept of extension is bit outdated and in real life practical only to some point.

http://en.wikipedia.org/wiki/Comparison_of_container_formats