[FFmpeg-devel] [PATCH 2/7] sws: add jobs option, distinct from threads

[rcombs]

This allows for more efficient use of asymmetric-multiprocessing systems.
---
 libswscale/options.c          | 2 ++
 libswscale/swscale_internal.h | 1 +
 libswscale/utils.c            | 9 ++++++---
 libswscale/version.h          | 2 +-
 4 files changed, 10 insertions(+), 4 deletions(-)

diff --git a/libswscale/options.c b/libswscale/options.c
index 4d41b835b1..5765daa100 100644
--- a/libswscale/options.c
+++ b/libswscale/options.c
@@ -81,6 +81,8 @@ static const AVOption swscale_options[] = {
 
     { "threads",         "number of threads",             OFFSET(nb_threads),   AV_OPT_TYPE_INT, {.i64 = 1 }, 0, INT_MAX, VE, "threads" },
         { "auto",        NULL,                            0,                  AV_OPT_TYPE_CONST, {.i64 = 0 },    .flags = VE, "threads" },
+    { "jobs",            "number of jobs",                OFFSET(nb_jobs),      AV_OPT_TYPE_INT, {.i64 = 0 }, 0, INT_MAX, VE, "jobs" },
+        { "auto",        NULL,                            0,                  AV_OPT_TYPE_CONST, {.i64 = 0 },    .flags = VE, "jobs" },
 
     { NULL }
 };
diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index abeebbb002..602082e12c 100644
--- a/libswscale/swscale_internal.h
+++ b/libswscale/swscale_internal.h
@@ -339,6 +339,7 @@ typedef struct SwsContext {
     int vChrDrop;                 ///< Binary logarithm of extra vertical subsampling factor in source image chroma planes specified by user.
     int sliceDir;                 ///< Direction that slices are fed to the scaler (1 = top-to-bottom, -1 = bottom-to-top).
     int nb_threads;               ///< Number of threads used for scaling
+    int nb_jobs;                  ///< Number of slice jobs used for scaling
     double param[2];              ///< Input parameters for scaling algorithms that need them.
 
     AVFrame *frame_src;
diff --git a/libswscale/utils.c b/libswscale/utils.c
index 45baa22b23..c9ff9db957 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -1277,18 +1277,21 @@ static int context_init_threaded(SwsContext *c,
                                     ff_sws_slice_worker, NULL, c->nb_threads);
     if (ret == AVERROR(ENOSYS)) {
         c->nb_threads = 1;
+        c->nb_jobs = 1;
         return 0;
     } else if (ret < 0)
         return ret;
 
     c->nb_threads = ret;
+    if (c->nb_jobs < 1)
+        c->nb_jobs = av_cpu_job_count();
 
-    c->slice_ctx = av_calloc(c->nb_threads, sizeof(*c->slice_ctx));
-    c->slice_err = av_calloc(c->nb_threads, sizeof(*c->slice_err));
+    c->slice_ctx = av_calloc(c->nb_jobs, sizeof(*c->slice_ctx));
+    c->slice_err = av_calloc(c->nb_jobs, sizeof(*c->slice_err));
     if (!c->slice_ctx || !c->slice_err)
         return AVERROR(ENOMEM);
 
-    for (int i = 0; i < c->nb_threads; i++) {
+    for (int i = 0; i < c->nb_jobs; i++) {
         c->slice_ctx[i] = sws_alloc_context();
         if (!c->slice_ctx[i])
             return AVERROR(ENOMEM);
diff --git a/libswscale/version.h b/libswscale/version.h
index 9bb3b171a7..4529a2d7d4 100644
--- a/libswscale/version.h
+++ b/libswscale/version.h
@@ -29,7 +29,7 @@
 #include "version_major.h"
 
 #define LIBSWSCALE_VERSION_MINOR   8
-#define LIBSWSCALE_VERSION_MICRO 112
+#define LIBSWSCALE_VERSION_MICRO 113
 
 #define LIBSWSCALE_VERSION_INT  AV_VERSION_INT(LIBSWSCALE_VERSION_MAJOR, \
                                                LIBSWSCALE_VERSION_MINOR, \
-- 
2.37.2