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Merge "Replace imprecise 32 bits calculations by 64 bits calculations"

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This commit is contained in:
Yaowu Xu 2014-04-08 07:14:21 -07:00 committed by Gerrit Code Review
commit 8f68468917
2 changed files with 4 additions and 13 deletions
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4
vp9/encoder/vp9_firstpass.c
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@ -917,9 +917,7 @@ int vp9_twopass_worst_quality(VP9_COMP *cpi, FIRSTPASS_STATS *fpstats,
return rc->worst_quality; // Highest value allowed
target_norm_bits_per_mb =
section_target_bandwitdh < (1 << 20)
? (section_target_bandwitdh << BPER_MB_NORMBITS) / num_mbs
: (section_target_bandwitdh / num_mbs) << BPER_MB_NORMBITS;
((uint64_t)section_target_bandwitdh << BPER_MB_NORMBITS) / num_mbs;
// Try and pick a max Q that will be high enough to encode the
// content at the given rate.

13
vp9/encoder/vp9_ratectrl.c
View File

@ -107,11 +107,7 @@ static int estimate_bits_at_q(int frame_kind, int q, int mbs,
double correction_factor) {
const int bpm = (int)(vp9_rc_bits_per_mb(frame_kind, q, correction_factor));
// Attempt to retain reasonable accuracy without overflow. The cutoff is
// chosen such that the maximum product of Bpm and MBs fits 31 bits. The
// largest Bpm takes 20 bits.
return (mbs > (1 << 11)) ? (bpm >> BPER_MB_NORMBITS) * mbs
: (bpm * mbs) >> BPER_MB_NORMBITS;
return ((uint64_t)bpm * mbs) >> BPER_MB_NORMBITS;
}
int vp9_rc_clamp_pframe_target_size(const VP9_COMP *const cpi, int target) {
@ -323,11 +319,8 @@ int vp9_rc_regulate_q(const VP9_COMP *cpi, int target_bits_per_frame,
// Calculate required scaling factor based on target frame size and size of
// frame produced using previous Q.
if (target_bits_per_frame >= (INT_MAX >> BPER_MB_NORMBITS))
// Case where we would overflow int
target_bits_per_mb = (target_bits_per_frame / cm->MBs) << BPER_MB_NORMBITS;
else
target_bits_per_mb = (target_bits_per_frame << BPER_MB_NORMBITS) / cm->MBs;
target_bits_per_mb =
((uint64_t)target_bits_per_frame << BPER_MB_NORMBITS) / cm->MBs;
i = active_best_quality;