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Fix loopfilter delta zero transitions

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Loopfilter deltas are initialized to zero on keyframes in the decoder.
The values then persist from the previous frame unless an update bit
is set in the bitstream. This data is not included in the entropy
data saved by the 'refresh entropy' bit in the bitstream, so it is
effectively an additional contextual element beyond the 3 ref-frames
and the entropy data.

The encoder was treating this delta update bit as update-if-nonzero,
meaning that the value would be refreshed even if it hadn't changed,
and more significantly, if the correct value for the delta changed
to zero, the update wouldn't be sent, and the decoder would preserve
the last (presumably non-zero) value.

This patch updates the encoder to send an update only if the value
has changed from the previously transmitted value. It also forces the
value to be transmitted in error resilient mode, to account for lost
context in the event of lost frames.

Change-Id: I56671d5b42965d0166ac226765dbfce3e5301868
This commit is contained in:
John Koleszar 2010-09-29 13:04:04 -04:00
parent 7288cdf79d
commit b9be7a464f
3 changed files with 20 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
vp8/common/blockd.h
View File

@ -262,9 +262,9 @@ typedef struct
unsigned char mode_ref_lf_delta_update;
// Delta values have the range +/- MAX_LOOP_FILTER
//char ref_lf_deltas[MAX_REF_LF_DELTAS]; // 0 = Intra, Last, GF, ARF
//char mode_lf_deltas[MAX_MODE_LF_DELTAS]; // 0 = BPRED, ZERO_MV, MV, SPLIT
signed char last_ref_lf_deltas[MAX_REF_LF_DELTAS]; // 0 = Intra, Last, GF, ARF
signed char ref_lf_deltas[MAX_REF_LF_DELTAS]; // 0 = Intra, Last, GF, ARF
signed char last_mode_lf_deltas[MAX_MODE_LF_DELTAS]; // 0 = BPRED, ZERO_MV, MV, SPLIT
signed char mode_lf_deltas[MAX_MODE_LF_DELTAS]; // 0 = BPRED, ZERO_MV, MV, SPLIT
// Distance of MB away from frame edges

14
vp8/encoder/bitstream.c
View File

@ -1490,9 +1490,11 @@ void vp8_pack_bitstream(VP8_COMP *cpi, unsigned char *dest, unsigned long *size)
if (xd->mode_ref_lf_delta_enabled)
{
// Do the deltas need to be updated
vp8_write_bit(bc, (xd->mode_ref_lf_delta_update) ? 1 : 0);
int send_update = xd->mode_ref_lf_delta_update
|| cpi->oxcf.error_resilient_mode;
if (xd->mode_ref_lf_delta_update)
vp8_write_bit(bc, send_update);
if (send_update)
{
int Data;
@ -1502,8 +1504,10 @@ void vp8_pack_bitstream(VP8_COMP *cpi, unsigned char *dest, unsigned long *size)
Data = xd->ref_lf_deltas[i];
// Frame level data
if (Data)
if (xd->ref_lf_deltas[i] != xd->last_ref_lf_deltas[i]
|| cpi->oxcf.error_resilient_mode)
{
xd->last_ref_lf_deltas[i] = xd->ref_lf_deltas[i];
vp8_write_bit(bc, 1);
if (Data > 0)
@ -1527,8 +1531,10 @@ void vp8_pack_bitstream(VP8_COMP *cpi, unsigned char *dest, unsigned long *size)
{
Data = xd->mode_lf_deltas[i];
if (Data)
if (xd->mode_lf_deltas[i] != xd->last_mode_lf_deltas[i]
|| cpi->oxcf.error_resilient_mode)
{
xd->last_mode_lf_deltas[i] = xd->mode_lf_deltas[i];
vp8_write_bit(bc, 1);
if (Data > 0)

20
vp8/encoder/onyx_if.c
View File

@ -272,6 +272,8 @@ static void setup_features(VP8_COMP *cpi)
cpi->mb.e_mbd.mode_ref_lf_delta_update = 0;
vpx_memset(cpi->mb.e_mbd.ref_lf_deltas, 0, sizeof(cpi->mb.e_mbd.ref_lf_deltas));
vpx_memset(cpi->mb.e_mbd.mode_lf_deltas, 0, sizeof(cpi->mb.e_mbd.mode_lf_deltas));
vpx_memset(cpi->mb.e_mbd.last_ref_lf_deltas, 0, sizeof(cpi->mb.e_mbd.ref_lf_deltas));
vpx_memset(cpi->mb.e_mbd.last_mode_lf_deltas, 0, sizeof(cpi->mb.e_mbd.mode_lf_deltas));
// jbb trial !
mode_ref_lf_test_function(cpi);
@ -4093,6 +4095,9 @@ static void encode_frame_to_data_rate
{
int i;
// Reset the loop filter deltas and segmentation map
setup_features(cpi);
// If segmentation is enabled force a map update for key frames
if (cpi->mb.e_mbd.segmentation_enabled)
{
@ -4100,12 +4105,6 @@ static void encode_frame_to_data_rate
cpi->mb.e_mbd.update_mb_segmentation_data = 1;
}
// If mode or reference frame based loop filter deltas are enabled then force an update for key frames.
if (cpi->mb.e_mbd.mode_ref_lf_delta_enabled)
{
cpi->mb.e_mbd.mode_ref_lf_delta_update = 1;
}
// The alternate reference frame cannot be active for a key frame
cpi->source_alt_ref_active = FALSE;
@ -4527,6 +4526,9 @@ static void encode_frame_to_data_rate
// Clear the Alt reference frame active flag when we have a key frame
cpi->source_alt_ref_active = FALSE;
// Reset the loop filter deltas and segmentation map
setup_features(cpi);
// If segmentation is enabled force a map update for key frames
if (cpi->mb.e_mbd.segmentation_enabled)
{
@ -4534,12 +4536,6 @@ static void encode_frame_to_data_rate
cpi->mb.e_mbd.update_mb_segmentation_data = 1;
}
// If mode or reference frame based loop filter deltas are enabled then force an update for key frames.
if (cpi->mb.e_mbd.mode_ref_lf_delta_enabled)
{
cpi->mb.e_mbd.mode_ref_lf_delta_update = 1;
}
vp8_restore_coding_context(cpi);
Q = vp8_regulate_q(cpi, cpi->this_frame_target);