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Fix bug causing unnecessary copying of memory

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This bug caused a single tiles worth of lcu_info_t structs to be copied
unnecessarily for every LCU in the frame. This obviously caused huge
memory bandwidth issues when coding large frames without tiles. The
effect was minimized somewhat with a large number of tiles, because
only the current tile was copied.

From context it is clear that this piece of code was supposed to copy
a single tile or frame, once the frame was done, but because it was
placed in a function which is called for every LCU, it copied the data
for the LCU, but also lots of extra stuff.

The fix is to copy only the current LCU instead of the whole tile.
This commit is contained in:
Ari Koivula 2015-09-16 18:15:54 +03:00
parent d8b50d6951
commit 513e80bcca
1 changed files with 12 additions and 4 deletions
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16
src/encoderstate.c
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@ -247,6 +247,8 @@ static void encoder_state_worker_encode_lcu(void * opaque) {
// Copy LCU cu_array to main states cu_array, because that is the only one
// which is given to the next frame through image_list_t.
{
PERFORMANCE_MEASURE_START(KVZ_PERF_FRAME);
encoder_state_t *main_state = state;
while (main_state->parent) main_state = main_state->parent;
assert(main_state != state);
@ -256,11 +258,17 @@ static void encoder_state_worker_encode_lcu(void * opaque) {
unsigned main_width_in_scu = main_state->tile->frame->width_in_lcu << MAX_DEPTH;
unsigned tile_x = state->tile->lcu_offset_x;
unsigned tile_y = state->tile->lcu_offset_y;
for (unsigned y = 0; y < child_height_in_scu; ++y) {
cu_info_t *main_row = &main_state->tile->frame->cu_array->data[tile_x + (tile_y + y) * main_width_in_scu];
cu_info_t *child_row = &state->tile->frame->cu_array->data[y * child_width_in_scu];
memcpy(main_row, child_row, sizeof(cu_info_t) * child_width_in_scu);
unsigned x = lcu->position.x << MAX_DEPTH;
unsigned y = lcu->position.y << MAX_DEPTH;
for (unsigned lcu_row = 0; lcu_row < 8; ++lcu_row) {
cu_info_t *main_row = &main_state->tile->frame->cu_array->data[x + tile_x + (y + tile_y + lcu_row) * main_width_in_scu];
cu_info_t *child_row = &state->tile->frame->cu_array->data[x + (y + lcu_row) * child_width_in_scu];
memcpy(main_row, child_row, sizeof(cu_info_t) * 8);
}
PERFORMANCE_MEASURE_END(KVZ_PERF_FRAME, state->encoder_control->threadqueue, "type=copy_cuinfo,frame=%d,tile=%d", state->global->frame, state->tile->id);
}
//Now write data to bitstream (required to have a correct CABAC state)