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Assign boost to GF bit allocation if past frame had no ARF.

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Modify the second-pass code to provide a full golden-frame (GF) bit
allocation boost if the past GF group (GFG) had no alt-ref frame (ARF),
even if the current GFG does contain and ARF.

This mostly has no effect on clips, since switching ARFs on/off between
GFGs is not very common. Has a positive effect on e.g. cheer (+0.45 SSIM
at 600kbps) and football (+0.25 SSIM at 600kbps), particularly at high
bitrates. Has a negative effect (-0.04 SSIM at 300kbps) at pamphlet,
which appears only marginally related to this patch, and crew (-0.1 SSIM
at 700kbps).

Change-Id: I2e32899638b59f857e26efeac18a82e0c0b77089
This commit is contained in:
Ronald S. Bultje 2011-06-16 13:01:27 -04:00
parent eb645abeac
commit 87fd66bb0e
1 changed files with 26 additions and 31 deletions
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57
vp8/encoder/firstpass.c
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@ -1722,14 +1722,15 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
cpi->twopass.modified_error_used += gf_group_err;
// Assign bits to the arf or gf.
{
for (i = 0; i <= (cpi->source_alt_ref_pending && cpi->common.frame_type != KEY_FRAME); i++) {
int Boost;
int frames_in_section;
int allocation_chunks;
int Q = (cpi->oxcf.fixed_q < 0) ? cpi->last_q[INTER_FRAME] : cpi->oxcf.fixed_q;
int gf_bits;
// For ARF frames
if (cpi->source_alt_ref_pending)
if (cpi->source_alt_ref_pending && i == 0)
{
Boost = (cpi->gfu_boost * 3 * GFQ_ADJUSTMENT) / (2 * 100);
//Boost += (cpi->baseline_gf_interval * 25);
@ -1768,7 +1769,7 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
}
// Calculate the number of bits to be spent on the gf or arf based on the boost number
cpi->twopass.gf_bits = (int)((double)Boost * (cpi->twopass.gf_group_bits / (double)allocation_chunks));
gf_bits = (int)((double)Boost * (cpi->twopass.gf_group_bits / (double)allocation_chunks));
// If the frame that is to be boosted is simpler than the average for
// the gf/arf group then use an alternative calculation
@ -1786,9 +1787,9 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
alt_gf_bits = (int)((double)Boost * (alt_gf_grp_bits /
(double)allocation_chunks));
if (cpi->twopass.gf_bits > alt_gf_bits)
if (gf_bits > alt_gf_bits)
{
cpi->twopass.gf_bits = alt_gf_bits;
gf_bits = alt_gf_bits;
}
}
// Else if it is harder than other frames in the group make sure it at
@ -1801,16 +1802,29 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
mod_frame_err /
DOUBLE_DIVIDE_CHECK((double)cpi->twopass.kf_group_error_left));
if (alt_gf_bits > cpi->twopass.gf_bits)
if (alt_gf_bits > gf_bits)
{
cpi->twopass.gf_bits = alt_gf_bits;
gf_bits = alt_gf_bits;
}
}
// Dont allow a negative value for gf_bits
if (cpi->twopass.gf_bits < 0)
cpi->twopass.gf_bits = 0;
if (gf_bits < 0)
gf_bits = 0;
gf_bits += cpi->min_frame_bandwidth; // Add in minimum for a frame
if (i == 0)
{
cpi->twopass.gf_bits = gf_bits;
}
if (i == 1 || (!cpi->source_alt_ref_pending && (cpi->common.frame_type != KEY_FRAME)))
{
cpi->per_frame_bandwidth = gf_bits; // Per frame bit target for this frame
}
}
{
// Adjust KF group bits and error remainin
cpi->twopass.kf_group_error_left -= gf_group_err;
cpi->twopass.kf_group_bits -= cpi->twopass.gf_group_bits;
@ -1825,7 +1839,7 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
else
cpi->twopass.gf_group_error_left = gf_group_err;
cpi->twopass.gf_group_bits -= cpi->twopass.gf_bits;
cpi->twopass.gf_group_bits -= cpi->twopass.gf_bits - cpi->min_frame_bandwidth;
if (cpi->twopass.gf_group_bits < 0)
cpi->twopass.gf_group_bits = 0;
@ -1841,13 +1855,6 @@ static void define_gf_group(VP8_COMP *cpi, FIRSTPASS_STATS *this_frame)
}
else
cpi->twopass.mid_gf_extra_bits = 0;
cpi->twopass.gf_bits += cpi->min_frame_bandwidth; // Add in minimum for a frame
}
if (!cpi->source_alt_ref_pending && (cpi->common.frame_type != KEY_FRAME)) // Normal GF and not a KF
{
cpi->per_frame_bandwidth = cpi->twopass.gf_bits; // Per frame bit target for this frame
}
// Adjustment to estimate_max_q based on a measure of complexity of the section
@ -1998,22 +2005,10 @@ void vp8_second_pass(VP8_COMP *cpi)
if (cpi->source_alt_ref_pending && (cpi->common.frame_type != KEY_FRAME))
{
// Assign a standard frames worth of bits from those allocated to the GF group
int bak = cpi->per_frame_bandwidth;
vpx_memcpy(&this_frame_copy, &this_frame, sizeof(this_frame));
assign_std_frame_bits(cpi, &this_frame_copy);
// If appropriate (we are switching into ARF active but it was not previously active) apply a boost for the gf at the start of the group.
//if ( !cpi->source_alt_ref_active && (cpi->gfu_boost > 150) )
if (FALSE)
{
int extra_bits;
int pct_extra = (cpi->gfu_boost - 100) / 50;
pct_extra = (pct_extra > 20) ? 20 : pct_extra;
extra_bits = (cpi->twopass.gf_group_bits * pct_extra) / 100;
cpi->twopass.gf_group_bits -= extra_bits;
cpi->per_frame_bandwidth += extra_bits;
}
cpi->per_frame_bandwidth = bak;
}
}