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