Andreas Rheinhardt: > Ramiro Polla: >> On Tue, Mar 4, 2025 at 6:05 PM Andreas Rheinhardt >> <andreas.rheinha...@outlook.com> wrote: >>> Ramiro Polla: >>>> >>>> On 3/4/25 14:42, Andreas Rheinhardt wrote: >>>>> (Mostly trivial) patches attached. A branch is at >>>>> https://github.com/mkver/FFmpeg/tree/mpegvideo_misc >>>> >>>> >>>> [PATCH 10/40] avcodec/mpegvideo_enc: Move default_mv_penalty to h261enc.c >>>> >>>>> diff --git a/libavcodec/h261enc.c b/libavcodec/h261enc.c >>>>> index dabab9d80a..e33bf35a8a 100644 >>>>> --- a/libavcodec/h261enc.c >>>>> +++ b/libavcodec/h261enc.c >>>>> @@ -46,6 +46,7 @@ static struct VLCLUT { >>>>> uint16_t code; >>>>> } vlc_lut[H261_MAX_RUN + 1][32 /* 0..2 * H261_MAX_LEN are used */]; >>>>> >>>>> +static uint8_t mv_penalty[MAX_FCODE + 1][MAX_DMV * 2 + 1]; >>>>> static uint8_t uni_h261_rl_len [64 * 128]; >>>>> static uint8_t uni_h261_rl_len_last[64 * 128]; >>>>> static uint8_t h261_mv_codes[64][2]; >>>>> @@ -370,6 +371,8 @@ av_cold int ff_h261_encode_init(MpegEncContext *s) >>>>> s->max_qcoeff = 127; >>>>> s->ac_esc_length = H261_ESC_LEN; >>>>> >>>>> + s->me.mv_penalty = mv_penalty; >>>>> + >>>>> s->intra_ac_vlc_length = s->inter_ac_vlc_length = >>>>> uni_h261_rl_len; >>>>> s->intra_ac_vlc_last_length = s->inter_ac_vlc_last_length = >>>>> uni_h261_rl_len_last; >>>>> ff_thread_once(&init_static_once, h261_encode_init_static); >>>> >>>> This global mv_penalty doesn't seem to be ever initialized; it could be >>>> declared const. >>> >>> But then it would no longer be placed in .bss, but instead in .rodata >>> and increase binary size. >> >> Wow, that's a huge array. >> >>>> But it also makes me think that whatever code is using this mv_penalty, >>>> which is always set to zero, might be calculating things wrong. >>>> >>> >>> It is obviously done to avoid branches for the codecs that matter. H.261 >>> does not matter much. Apart from that, it is a very cheap workaround >>> given that this table is .bss. >> >> Could you add some comments (either next to the declaration or the >> commit message) to reflect this? (save space from .rodata, and this >> being a noop for h.261, which doesn't matter that much) >> >>>> [PATCH 15/40] avcodec/ituh263enc: Make SVQ1+Snowenc stop calling >>>> ff_h263_encode_init() >>>> >>>>> diff --git a/libavcodec/ituh263enc.c b/libavcodec/ituh263enc.c >>>>> index 02da090ba4..8313b2c2c1 100644 >>>>> --- a/libavcodec/ituh263enc.c >>>>> +++ b/libavcodec/ituh263enc.c >>>>> @@ -65,6 +65,127 @@ static uint8_t uni_h263_inter_rl_len [64*64*2*2]; >>>> [...] >>>>> +static av_cold void h263_encode_init_static(void) >>>>> +{ >>>>> + static uint8_t rl_intra_table[2][2 * MAX_RUN + MAX_LEVEL + 3]; >>>>> + >>>>> + ff_rl_init(&ff_rl_intra_aic, rl_intra_table); >>>>> + ff_h263_init_rl_inter(); >>>>> + >>>>> + init_uni_h263_rl_tab(&ff_rl_intra_aic, uni_h263_intra_aic_rl_len); >>>>> + init_uni_h263_rl_tab(&ff_h263_rl_inter, uni_h263_inter_rl_len); >>>>> + >>>>> + init_mv_penalty_and_fcode(); >>>>> +} >>>>> + >>>>> +av_cold const uint8_t (*ff_h263_get_mv_penalty(void))[MAX_DMV*2+1] >>>>> +{ >>>>> + static AVOnce init_static_once = AV_ONCE_INIT; >>>>> + >>>>> + ff_thread_once(&init_static_once, h263_encode_init_static); >>>>> + >>>>> + return mv_penalty; >>>>> +} >>>>> + >>>> >>>> This approach kind of hides the rest of h263_encode_init_static() inside >>>> ff_h263_get_mv_penalty(), so the name is a bit misleading. I'd expect >>>> h263 to still call some init function and ff_h263_get_mv_penalty(), and >>>> SVQ1 and Snow to only call ff_h263_get_mv_penalty(), which would only >>>> take care of the mv_penalty table. >>>> >>> >>> This would entail using another AVOnce etc. and this level of >>> granularity is just not worth it. >> >> Ok. >> >>> The name is chosen for what it does for an outsider (i.e. from the >>> perspective of svq1enc or snowenc, not the actual H.263 based encoders). >> >> I'm still not quite happy with the name and how it's used, but it's >> good enough so I won't insist. >> >>>> [PATCH 20/40] avcodec/mpeg4video: Split ff_mpeg4_pred_dc() >>>> >>>>> diff --git a/libavcodec/mpeg4videoenc.c b/libavcodec/mpeg4videoenc.c >>>>> index 64fb96a0cf..26f9b40ff7 100644 >>>>> --- a/libavcodec/mpeg4videoenc.c >>>>> +++ b/libavcodec/mpeg4videoenc.c >>>>> @@ -806,8 +806,14 @@ void ff_mpeg4_encode_mb(MpegEncContext *s, >>>>> int16_t block[6][64], >>>>> const uint8_t *scan_table[6]; >>>>> int i; >>>>> >>>>> - for (i = 0; i < 6; i++) >>>>> - dc_diff[i] = ff_mpeg4_pred_dc(s, i, block[i][0], &dir[i], >>>>> 1); >>>>> + for (int i = 0; i < 6; i++) { >>>> >>>> Redeclaring i inside for. >>> >>> There are other loops which use this i as loop variable. The shadowing >>> is IMO less bad than keeping loops in their current form (with iterators >>> that don't have loop-scope). >> >> Agreed. I also prefer scoped iterators. > > I added a comment to #10 and modified #18 as described. I also changed > #21 to protect the macro in parentheses and simplified the FF_RC_OFFSET > macro in #31. Furthermore, there are now five more patches. All > attached. https://github.com/mkver/FFmpeg/tree/mpegvideo_misc has been > force-pushed. > Will apply this patchset (with the issues pointed out by Ramiro fixed) tomorrow unless there are objections.
- Andreas _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
