From 616251c924d9ea9bb0fcc4a5cf6ad241873500c6 Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Thu, 7 Jan 2010 15:43:49 +0000 Subject: [PATCH] Document decide_ac_pred() and restore_ac_coeffs(). Originally committed as revision 21063 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/h263.c | 14 ++++++++++++++ 1 file changed, 14 insertions(+) diff --git a/libavcodec/h263.c b/libavcodec/h263.c index a3426ceb4d..198b34682e 100644 --- a/libavcodec/h263.c +++ b/libavcodec/h263.c @@ -368,6 +368,15 @@ static inline int get_block_rate(MpegEncContext * s, DCTELEM block[64], int bloc return rate; } + +/** + * Restores the ac coefficients in block that have been changed by decide_ac_pred(). + * This function also restores s->block_last_index. + * @param[in,out] block MB coefficients, these will be restored + * @param[in] dir ac prediction direction for each 8x8 block + * @param[out] st scantable for each 8x8 block + * @param[in] zigzag_last_index index refering to the last non zero coefficient in zigzag order + */ static inline void restore_ac_coeffs(MpegEncContext * s, DCTELEM block[6][64], int dir[6], uint8_t *st[6], int zigzag_last_index[6]) { int i, n; @@ -393,6 +402,11 @@ static inline void restore_ac_coeffs(MpegEncContext * s, DCTELEM block[6][64], i /** * Returns the optimal value (0 or 1) for the ac_pred element for the given MB in mpeg4. + * This function will also update s->block_last_index and s->ac_val. + * @param[in,out] block MB coefficients, these will be updated if 1 is returned + * @param[in] dir ac prediction direction for each 8x8 block + * @param[out] st scantable for each 8x8 block + * @param[out] zigzag_last_index index refering to the last non zero coefficient in zigzag order */ static inline int decide_ac_pred(MpegEncContext * s, DCTELEM block[6][64], int dir[6], uint8_t *st[6], int zigzag_last_index[6]) {