2011-09-30 19:10:28 +03:00
|
|
|
The official guide to swresample for confused developers.
|
|
|
|
|
=========================================================
|
|
|
|
|
|
|
|
|
|
Current (simplified) Architecture:
|
|
|
|
|
---------------------------------
|
|
|
|
|
Input
|
|
|
|
|
v
|
|
|
|
|
__________________/|\___________
|
|
|
|
|
/ | \
|
|
|
|
|
/ input sample format convert v
|
|
|
|
|
/ | ___________/
|
|
|
|
|
| |/
|
|
|
|
|
| v
|
|
|
|
|
| ___________/|\___________ _____________
|
|
|
|
|
| / | \ | |
|
|
|
|
|
| Rematrix | resample <---->| Buffers |
|
|
|
|
|
| \___________ | ___________/ |_____________|
|
|
|
|
|
v \|/
|
|
|
|
|
Special Converter v
|
|
|
|
|
v ___________/|\___________ _____________
|
|
|
|
|
| / | \ | |
|
|
|
|
|
| Rematrix | resample <---->| Buffers |
|
|
|
|
|
| \___________ | ___________/ |_____________|
|
|
|
|
|
| \|/
|
|
|
|
|
| v
|
|
|
|
|
| |\___________
|
|
|
|
|
\ | \
|
|
|
|
|
\ output sample format convert v
|
|
|
|
|
\_________________ | ___________/
|
|
|
|
|
\|/
|
|
|
|
|
v
|
|
|
|
|
Output
|
|
|
|
|
|
|
|
|
|
Planar/Packed convertion is done when needed during sample format convertion
|
|
|
|
|
Every step can be skiped without memcpy when its not needed.
|
|
|
|
|
Either Resampling and Rematrixing can be performed first depending on which
|
|
|
|
|
way its faster.
|
|
|
|
|
The Buffers are needed for resampling due to resamplng being a process that
|
|
|
|
|
requires future and past data, it thus also introduces inevitably a delay when
|
|
|
|
|
used.
|
|
|
|
|
Internally 32bit float and 16bit int is supported currently, other formats can
|
|
|
|
|
easily be added
|
|
|
|
|
Externally all sample formats in packed and planar configuration are supported
|
|
|
|
|
Its also trivial to add special converters for common cases
|
2011-10-06 01:32:01 +03:00
|
|
|
If only sample format and or packed/planar convertion is needed it
|
|
|
|
|
is performed from input to output directly in a single pass with no intermediates.
|
