Prevent encoder crash caused by row tile dependencies
In multi-thread case, the encoder may crash if using encoder option
tile-rows > 0. To prevent that, force tile-rows=0 in this situation.
This is a workaround for WebM issue 1095:
https://bugs.chromium.org/p/webm/issues/detail?id=1095
The further fix can be done by adding synchronizations after a tile
row is encoded. But this will hurt multi-threaded encoder performance.
So, it is recommended to use tile-rows=0 while encoding with threads
> 1.
Change-Id: I656cbcc200f8d0410d09530e7981ad8f32fe7bc9
diff --git a/vp9/vp9_cx_iface.c b/vp9/vp9_cx_iface.c
index 624d5c9..07de29b 100644
--- a/vp9/vp9_cx_iface.c
+++ b/vp9/vp9_cx_iface.c
@@ -486,7 +486,13 @@
oxcf->content = extra_cfg->content;
oxcf->tile_columns = extra_cfg->tile_columns;
- oxcf->tile_rows = extra_cfg->tile_rows;
+
+ // The dependencies between row tiles cause error in multi-threaded encoding.
+ // For now, it is forced to be 0 in this case.
+ if (oxcf->max_threads > 1 && oxcf->tile_columns > 0)
+ oxcf->tile_rows = 0;
+ else
+ oxcf->tile_rows = extra_cfg->tile_rows;
oxcf->error_resilient_mode = cfg->g_error_resilient;
oxcf->frame_parallel_decoding_mode = extra_cfg->frame_parallel_decoding_mode;
diff --git a/vpxenc.c b/vpxenc.c
index f24b180..50e7c7f 100644
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -380,7 +380,8 @@
static const arg_def_t tile_cols = ARG_DEF(
NULL, "tile-columns", 1, "Number of tile columns to use, log2");
static const arg_def_t tile_rows = ARG_DEF(
- NULL, "tile-rows", 1, "Number of tile rows to use, log2");
+ NULL, "tile-rows", 1,
+ "Number of tile rows to use, log2 (set to 0 while threads > 1)");
static const arg_def_t lossless = ARG_DEF(
NULL, "lossless", 1, "Lossless mode (0: false (default), 1: true)");
static const arg_def_t frame_parallel_decoding = ARG_DEF(
