[FFmpeg-soc] [soc]: r5533 - in indeo5: TODO description
diego
subversion at mplayerhq.hu
Sun Dec 13 12:21:05 CET 2009
Author: diego
Date: Sun Dec 13 12:21:05 2009
New Revision: 5533
Log:
cosmetics: Break overly long lines.
Modified:
indeo5/TODO
indeo5/description
Modified: indeo5/TODO
==============================================================================
--- indeo5/TODO Sun Dec 13 05:24:02 2009 (r5532)
+++ indeo5/TODO Sun Dec 13 12:21:05 2009 (r5533)
@@ -1,5 +1,9 @@
Please read my comments named "description" BEFORE doing anything! Thanks!
-Some small steps needed to be completed in order to make FFmpeg able to decode indeo5 videos:
+Some small steps needed to be completed in order to make FFmpeg able to
+decode indeo5 videos:
-* split the 5/3 wavelet synthesis filter out of the snow source (see snow.c:spatial_compose53i) and adapt it to indeo5. The indeo5's high-pass coefficients must be upscaled by -2 in this case before those can be passed to that filter.
+* split the 5/3 wavelet synthesis filter out of the snow source (see
+ snow.c:spatial_compose53i) and adapt it to indeo5. The indeo5's
+ high-pass coefficients must be upscaled by -2 in this case before
+ those can be passed to that filter.
Modified: indeo5/description
==============================================================================
--- indeo5/description Sun Dec 13 05:24:02 2009 (r5532)
+++ indeo5/description Sun Dec 13 12:21:05 2009 (r5533)
@@ -6,20 +6,36 @@ Description of the files:
Indeo5 docs:
-------------
-There is a basic indeo5 documentation being currently in progress. It can be found here:
+There is a basic indeo5 documentation being currently in progress. It
+can be found here:
http://wiki.multimedia.cx/index.php?title=Indeo_5
Please be aware of the following important design specifics of the indeo5 codec:
-1. Indeo5 operates on the pixels in the range [-128...127]. It was made in order to make the values compatible with the slant transform which requires both negative and positive numbers. The conversions look like this:
+1. Indeo5 operates on the pixels in the range [-128...127]. It was made in
+ order to make the values compatible with the slant transform which requires
+ both negative and positive numbers. The conversions look like this:
encoder -> internal_pixel = pixel - 128;
decoder -> pixel = clip((internal_pixel + 128), 0, 255);
-2. The 5/3 wavelet filter used for splitting the signal into several bands requires at least 10-bit precision of the internal pixel values. Therefore my decoder operates completely on the 16-bit pixels by using the IDWTELEM data type. Only at the last step (output a plane) those pixels will be clipped to fit the 8-bit output values. This design requires special motion compensation routines operating on the IDWTELEM data type. The internal motion compensation routines (put_pixels stuff) cannot be used in this case!!!
+2. The 5/3 wavelet filter used for splitting the signal into several bands
+ requires at least 10-bit precision of the internal pixel values.
+ Therefore my decoder operates completely on the 16-bit pixels by using the
+ IDWTELEM data type. Only at the last step (output a plane) those pixels
+ will be clipped to fit the 8-bit output values. This design requires
+ special motion compensation routines operating on the IDWTELEM data type.
+ The internal motion compensation routines (put_pixels stuff) cannot be
+ used in this case!!!
-3. The 5/3 wavelet filter of indeo5 differs from the standard one in that it scales the high-pass coefficients by the value of -1/2. It should be possible to reuse the Snow's code (see snow.c:spatial_compose53i) which implements the same wavelet but upscale the indeo5 coefficients by -2 before calling this function. Maybe it will be possible to integrate the upscale step directly into this function...
+3. The 5/3 wavelet filter of indeo5 differs from the standard one in that it
+ scales the high-pass coefficients by the value of -1/2. It should be
+ possible to reuse the Snow's code (see snow.c:spatial_compose53i) which
+ implements the same wavelet but upscale the indeo5 coefficients by -2
+ before calling this function. Maybe it will be possible to integrate the
+ upscale step directly into this function...
-4. Please work with debugging features (see "IVI_DEBUG" in my code) enabled in order to ensure you don't break anything!
+4. Please work with debugging features (see "IVI_DEBUG" in my code)
+ enabled in order to ensure you don't break anything!
For the further description please read the source or ask me...
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