From 3d43e42f293bd79a4b4cd93b499f438827481eb8 Mon Sep 17 00:00:00 2001 From: Ivan Kalvachev Date: Sun, 15 Feb 2009 18:30:39 +0000 Subject: Document all functions in mpegvideo_xvmc. Originally committed as revision 17340 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/mpegvideo_xvmc.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) (limited to 'libavcodec/mpegvideo_xvmc.c') diff --git a/libavcodec/mpegvideo_xvmc.c b/libavcodec/mpegvideo_xvmc.c index 1310c92bbf..d9b238ac0f 100644 --- a/libavcodec/mpegvideo_xvmc.c +++ b/libavcodec/mpegvideo_xvmc.c @@ -34,6 +34,9 @@ /** * Initializes the block field of the MpegEncContext pointer passed as * parameter after making sure that the data is not corrupted. + * In order to implement something like direct rendering instead of decodeing + * coefficients in s->blocks and then copy them, do that directly + * into the data_blocks array provided by xvmc. */ void ff_xvmc_init_block(MpegEncContext *s) { @@ -43,6 +46,10 @@ void ff_xvmc_init_block(MpegEncContext *s) s->block = (DCTELEM *)(render->data_blocks + render->next_free_data_block_num * 64); } +/** + * Fill individual block pointers, so there are no gaps in the data_block array + * in case not all blocks in MB are coded. + */ void ff_xvmc_pack_pblocks(MpegEncContext *s, int cbp) { int i, j = 0; @@ -59,6 +66,7 @@ void ff_xvmc_pack_pblocks(MpegEncContext *s, int cbp) } /** + * Find and store the surfaces that are used as reference frames. * This function should be called for every new field and/or frame. * It should be safe to call the function a few times for the same field. */ @@ -118,7 +126,9 @@ return -1; } /** - * This function should be called for every new field and/or frame. + * Complete frame/field rendering by passing any remaining blocks. + * Normally ff_draw_horiz_band() is called on each slice, however + * there may be some remaining blocks, for example put by error_resilience. * It should be safe to call the function a few times for the same field. */ void ff_xvmc_field_end(MpegEncContext *s) @@ -130,6 +140,10 @@ void ff_xvmc_field_end(MpegEncContext *s) ff_draw_horiz_band(s, 0, 0); } +/** + * Synthesize the data needed by XvMC to render one macroblock of data. + * Fill all relevent fields, if necessery do IDCT. + */ void ff_xvmc_decode_mb(MpegEncContext *s) { XvMCMacroBlock *mv_block; -- cgit v1.2.3