lavc: replace internal use of AV_CODEC_CAP_AUTO_THREADS with an internal cap

AV_CODEC_CAP_AUTO_THREADS was originally added in b4d44a45f9a to mark
codecs that spawn threads internally and are able to select an optimal
threads count by themselves (all such codecs are wrappers around
external libraries). It is used by lavc generic code to check whether it
should handle thread_count=0 itself or pass the zero directly to the
codec implementation. Within this meaning, it is clearly supposed to be
an internal cap rather than a public one, since from the viewpoint of a
libavcodec user, lavc ALWAYS handles thread_count=0. Whether it happens
in the generic code or within the codec internals is not a meaningful
difference for the caller.

External aspects of this flag will be dealt with in the following
commit.

18 files changed, 33 insertions, 13 deletions

diff --git a/libavcodec/internal.h b/libavcodec/internal.h
index 400ea508ef..b57b996816 100644
--- a/libavcodec/internal.h
+++ b/libavcodec/internal.h
@@ -74,6 +74,10 @@
  * uses ff_thread_report/await_progress().
  */
 #define FF_CODEC_CAP_ALLOCATE_PROGRESS      (1 << 6)
+/**
+ * Codec handles avctx->thread_count == 0 (auto) internally.
+ */
+#define FF_CODEC_CAP_AUTO_THREADS           (1 << 7)
 
 /**
  * AVCodec.codec_tags termination value
diff --git a/libavcodec/libaomdec.c b/libavcodec/libaomdec.c
index 1430a651fe..327a5e18fb 100644
--- a/libavcodec/libaomdec.c
+++ b/libavcodec/libaomdec.c
@@ -237,6 +237,7 @@ AVCodec ff_libaom_av1_decoder = {
     .close          = aom_free,
     .decode         = aom_decode,
     .capabilities   = AV_CODEC_CAP_AUTO_THREADS | AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .profiles       = NULL_IF_CONFIG_SMALL(ff_av1_profiles),
     .wrapper_name   = "libaom",
 };
diff --git a/libavcodec/libaomenc.c b/libavcodec/libaomenc.c
index 9a26b5f9ef..f99fdc0b73 100644
--- a/libavcodec/libaomenc.c
+++ b/libavcodec/libaomenc.c
@@ -1346,6 +1346,7 @@ AVCodec ff_libaom_av1_encoder = {
     .encode2        = aom_encode,
     .close          = aom_free,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .profiles       = NULL_IF_CONFIG_SMALL(ff_av1_profiles),
     .priv_class     = &class_aom,
     .defaults       = defaults,
diff --git a/libavcodec/libdav1d.c b/libavcodec/libdav1d.c
index 383e4557b4..93aeab4cb1 100644
--- a/libavcodec/libdav1d.c
+++ b/libavcodec/libdav1d.c
@@ -485,7 +485,8 @@ AVCodec ff_libdav1d_decoder = {
     .flush          = libdav1d_flush,
     .receive_frame  = libdav1d_receive_frame,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_SETS_PKT_DTS,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_SETS_PKT_DTS |
+                      FF_CODEC_CAP_AUTO_THREADS,
     .priv_class     = &libdav1d_class,
     .wrapper_name   = "libdav1d",
 };
diff --git a/libavcodec/libdavs2.c b/libavcodec/libdavs2.c
index 218f3ec239..f6a03df373 100644
--- a/libavcodec/libdavs2.c
+++ b/libavcodec/libdavs2.c
@@ -222,6 +222,7 @@ AVCodec ff_libdavs2_decoder = {
     .decode         = davs2_decode_frame,
     .flush          = davs2_flush,
     .capabilities   =  AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                      AV_PIX_FMT_NONE },
     .wrapper_name   = "libdavs2",
diff --git a/libavcodec/libkvazaar.c b/libavcodec/libkvazaar.c
index d94cf995c8..f75aa4eda3 100644
--- a/libavcodec/libkvazaar.c
+++ b/libavcodec/libkvazaar.c
@@ -341,7 +341,8 @@ AVCodec ff_libkvazaar_encoder = {
     .encode2          = libkvazaar_encode,
     .close            = libkvazaar_close,
 
-    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP |
+                        FF_CODEC_CAP_AUTO_THREADS,
 
     .wrapper_name     = "libkvazaar",
 };
diff --git a/libavcodec/libopenh264enc.c b/libavcodec/libopenh264enc.c
index cf485663e1..cb5deb8b50 100644
--- a/libavcodec/libopenh264enc.c
+++ b/libavcodec/libopenh264enc.c
@@ -448,7 +448,8 @@ AVCodec ff_libopenh264_encoder = {
     .encode2        = svc_encode_frame,
     .close          = svc_encode_close,
     .capabilities   = AV_CODEC_CAP_AUTO_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP |
+                      FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P,
                                                     AV_PIX_FMT_NONE },
     .defaults       = svc_enc_defaults,
diff --git a/libavcodec/librav1e.c b/libavcodec/librav1e.c
index 2d5acc7d8e..bd93073664 100644
--- a/libavcodec/librav1e.c
+++ b/libavcodec/librav1e.c
@@ -625,6 +625,6 @@ AVCodec ff_librav1e_encoder = {
     .defaults       = librav1e_defaults,
     .pix_fmts       = librav1e_pix_fmts,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_AUTO_THREADS,
     .wrapper_name   = "librav1e",
 };
diff --git a/libavcodec/libsvtav1.c b/libavcodec/libsvtav1.c
index eb6043bcac..4244ae1daa 100644
--- a/libavcodec/libsvtav1.c
+++ b/libavcodec/libsvtav1.c
@@ -561,6 +561,7 @@ AVCodec ff_libsvtav1_encoder = {
     .receive_packet = eb_receive_packet,
     .close          = eb_enc_close,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P,
                                                     AV_PIX_FMT_YUV420P10,
                                                     AV_PIX_FMT_NONE },
diff --git a/libavcodec/libuavs3d.c b/libavcodec/libuavs3d.c
index d77cc2192d..6bc0ba09f0 100644
--- a/libavcodec/libuavs3d.c
+++ b/libavcodec/libuavs3d.c
@@ -254,6 +254,7 @@ AVCodec ff_libuavs3d_decoder = {
     .close          = libuavs3d_end,
     .decode         = libuavs3d_decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .flush          = libuavs3d_flush,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                      AV_PIX_FMT_YUV420P10LE,
diff --git a/libavcodec/libvpxdec.c b/libavcodec/libvpxdec.c
index 86982325a7..8a4e4fd149 100644
--- a/libavcodec/libvpxdec.c
+++ b/libavcodec/libvpxdec.c
@@ -362,6 +362,7 @@ AVCodec ff_libvpx_vp8_decoder = {
     .close          = vpx_free,
     .decode         = vpx_decode,
     .capabilities   = AV_CODEC_CAP_AUTO_THREADS | AV_CODEC_CAP_DR1,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .wrapper_name   = "libvpx",
 };
 #endif /* CONFIG_LIBVPX_VP8_DECODER */
@@ -383,6 +384,7 @@ AVCodec ff_libvpx_vp9_decoder = {
     .close          = vpx_free,
     .decode         = vpx_decode,
     .capabilities   = AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .init_static_data = ff_vp9_init_static,
     .profiles       = NULL_IF_CONFIG_SMALL(ff_vp9_profiles),
     .wrapper_name   = "libvpx",
diff --git a/libavcodec/libvpxenc.c b/libavcodec/libvpxenc.c
index 02df4fe87b..df79839df5 100644
--- a/libavcodec/libvpxenc.c
+++ b/libavcodec/libvpxenc.c
@@ -1871,6 +1871,7 @@ AVCodec ff_libvpx_vp8_encoder = {
     .encode2        = vpx_encode,
     .close          = vpx_free,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUVA420P, AV_PIX_FMT_NONE },
     .priv_class     = &class_vp8,
     .defaults       = defaults,
@@ -1901,6 +1902,7 @@ AVCodec ff_libvpx_vp9_encoder = {
     .encode2        = vpx_encode,
     .close          = vpx_free,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .profiles       = NULL_IF_CONFIG_SMALL(ff_vp9_profiles),
     .priv_class     = &class_vp9,
     .defaults       = defaults,
diff --git a/libavcodec/libx264.c b/libavcodec/libx264.c
index 212ed7d015..f152e453ce 100644
--- a/libavcodec/libx264.c
+++ b/libavcodec/libx264.c
@@ -1204,6 +1204,7 @@ AVCodec ff_libx264_encoder = {
     .close            = X264_close,
     .capabilities     = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS |
                         AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
+    .caps_internal    = FF_CODEC_CAP_AUTO_THREADS,
     .priv_class       = &x264_class,
     .defaults         = x264_defaults,
 #if X264_BUILD < 153
@@ -1211,11 +1212,11 @@ AVCodec ff_libx264_encoder = {
 #else
     .pix_fmts         = pix_fmts_all,
 #endif
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_AUTO_THREADS
 #if X264_BUILD >= 158
-    .caps_internal    = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
-#else
-    .caps_internal    = FF_CODEC_CAP_INIT_CLEANUP,
+                      | FF_CODEC_CAP_INIT_THREADSAFE
 #endif
+                      ,
     .wrapper_name     = "libx264",
 };
 #endif
@@ -1242,11 +1243,11 @@ AVCodec ff_libx264rgb_encoder = {
     .priv_class     = &rgbclass,
     .defaults       = x264_defaults,
     .pix_fmts       = pix_fmts_8bit_rgb,
+    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_AUTO_THREADS
 #if X264_BUILD >= 158
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
-#else
-    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,
+                      | FF_CODEC_CAP_INIT_THREADSAFE
 #endif
+                      ,
     .wrapper_name   = "libx264",
 };
 #endif
@@ -1273,7 +1274,7 @@ AVCodec ff_libx262_encoder = {
     .priv_class       = &X262_class,
     .defaults         = x264_defaults,
     .pix_fmts         = pix_fmts_8bit,
-    .caps_internal    = FF_CODEC_CAP_INIT_CLEANUP,
+    .caps_internal    = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_AUTO_THREADS,
     .wrapper_name     = "libx264",
 };
 #endif
diff --git a/libavcodec/libx265.c b/libavcodec/libx265.c
index 686c205b6b..d502f47662 100644
--- a/libavcodec/libx265.c
+++ b/libavcodec/libx265.c
@@ -702,5 +702,6 @@ AVCodec ff_libx265_encoder = {
     .defaults         = x265_defaults,
     .capabilities     = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS |
                         AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE,
+    .caps_internal    = FF_CODEC_CAP_AUTO_THREADS,
     .wrapper_name     = "libx265",
 };
diff --git a/libavcodec/libxavs.c b/libavcodec/libxavs.c
index 752ff66dfa..12d5a5eb9e 100644
--- a/libavcodec/libxavs.c
+++ b/libavcodec/libxavs.c
@@ -476,6 +476,7 @@ AVCodec ff_libxavs_encoder = {
     .encode2        = XAVS_frame,
     .close          = XAVS_close,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
     .priv_class     = &xavs_class,
     .defaults       = xavs_defaults,
diff --git a/libavcodec/libxavs2.c b/libavcodec/libxavs2.c
index 8519f6925a..cd29d2b938 100644
--- a/libavcodec/libxavs2.c
+++ b/libavcodec/libxavs2.c
@@ -295,6 +295,7 @@ AVCodec ff_libxavs2_encoder = {
     .encode2        = xavs2_encode_frame,
     .close          = xavs2_close,
     .capabilities   = AV_CODEC_CAP_DELAY | AV_CODEC_CAP_AUTO_THREADS,
+    .caps_internal  = FF_CODEC_CAP_AUTO_THREADS,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
                                                      AV_PIX_FMT_NONE },
     .priv_class     = &libxavs2,
diff --git a/libavcodec/pthread.c b/libavcodec/pthread.c
index 572471586d..14b7cca4fe 100644
--- a/libavcodec/pthread.c
+++ b/libavcodec/pthread.c
@@ -56,7 +56,7 @@ static void validate_thread_parameters(AVCodecContext *avctx)
     } else if (avctx->codec->capabilities & AV_CODEC_CAP_SLICE_THREADS &&
                avctx->thread_type & FF_THREAD_SLICE) {
         avctx->active_thread_type = FF_THREAD_SLICE;
-    } else if (!(avctx->codec->capabilities & AV_CODEC_CAP_AUTO_THREADS)) {
+    } else if (!(avctx->codec->caps_internal & FF_CODEC_CAP_AUTO_THREADS)) {
         avctx->thread_count       = 1;
         avctx->active_thread_type = 0;
     }
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index 66d286565b..5d220ada4b 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -761,7 +761,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
             goto free_and_end;
         }
     }
-    if (!HAVE_THREADS && !(codec->capabilities & AV_CODEC_CAP_AUTO_THREADS))
+    if (!HAVE_THREADS && !(codec->caps_internal & FF_CODEC_CAP_AUTO_THREADS))
         avctx->thread_count = 1;
 
     if (avctx->codec->max_lowres < avctx->lowres || avctx->lowres < 0) {