[FFmpeg-cvslog] avcodec/amfenc: Implement async_depth option

[Cameron Gutman]

ffmpeg | branch: master | Cameron Gutman <aicommander at gmail.com> | Wed Nov  6 22:14:13 2024 -0600| [a40cbf979285f930354b71b8033d00c91f03af40] | committer: Dmitrii Ovchinnikov

avcodec/amfenc: Implement async_depth option

This option, which is also available on other FFmpeg hardware encoders,
allows the user to trade throughput for reduced output latency. This is
useful for ultra low latency applications like game streaming.

Signed-off-by: Cameron Gutman <aicommander at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=a40cbf979285f930354b71b8033d00c91f03af40
---

 libavcodec/amfenc.c      | 3 +--
 libavcodec/amfenc_av1.c  | 2 ++
 libavcodec/amfenc_h264.c | 3 +++
 libavcodec/amfenc_hevc.c | 2 ++
 4 files changed, 8 insertions(+), 2 deletions(-)

diff --git a/libavcodec/amfenc.c b/libavcodec/amfenc.c
index 03d75031f5..c8411902f4 100644
--- a/libavcodec/amfenc.c
+++ b/libavcodec/amfenc.c
@@ -274,7 +274,6 @@ static int amf_init_context(AVCodecContext *avctx)
     av_unused int ret;
 
     ctx->hwsurfaces_in_queue = 0;
-    ctx->hwsurfaces_in_queue_max = 16;
 
     // configure AMF logger
     // the return of these functions indicates old state and do not affect behaviour
@@ -329,7 +328,7 @@ static int amf_init_context(AVCodecContext *avctx)
             return AVERROR(ENOMEM);
 
         if (frames_ctx->initial_pool_size > 0)
-            ctx->hwsurfaces_in_queue_max = frames_ctx->initial_pool_size - 1;
+            ctx->hwsurfaces_in_queue_max = FFMIN(ctx->hwsurfaces_in_queue_max, frames_ctx->initial_pool_size - 1);
 
     } else if (avctx->hw_device_ctx) {
         AVHWDeviceContext *device_ctx = (AVHWDeviceContext*)avctx->hw_device_ctx->data;
diff --git a/libavcodec/amfenc_av1.c b/libavcodec/amfenc_av1.c
index 01b1f85747..7646d38d8a 100644
--- a/libavcodec/amfenc_av1.c
+++ b/libavcodec/amfenc_av1.c
@@ -97,6 +97,8 @@ static const AVOption options[] = {
     { "gop",                    "", 0, AV_OPT_TYPE_CONST, {.i64 = AMF_VIDEO_ENCODER_AV1_HEADER_INSERTION_MODE_GOP_ALIGNED       }, 0, 0, VE, .unit = "hdrmode" },
     { "frame",                  "", 0, AV_OPT_TYPE_CONST, {.i64 = AMF_VIDEO_ENCODER_AV1_HEADER_INSERTION_MODE_KEY_FRAME_ALIGNED }, 0, 0, VE, .unit = "hdrmode" },
 
+    { "async_depth",            "Set maximum encoding parallelism. Higher values increase output latency.", OFFSET(hwsurfaces_in_queue_max), AV_OPT_TYPE_INT, {.i64 = 16 }, 1, 16, VE },
+
     { "preencode",              "Enable preencode",     OFFSET(preencode),      AV_OPT_TYPE_BOOL, {.i64 = -1  }, -1, 1, VE},
     { "enforce_hrd",            "Enforce HRD",          OFFSET(enforce_hrd),    AV_OPT_TYPE_BOOL, {.i64 = -1  }, -1, 1, VE},
     { "filler_data",            "Filler Data Enable",   OFFSET(filler_data),    AV_OPT_TYPE_BOOL, {.i64 = -1  }, -1, 1, VE},
diff --git a/libavcodec/amfenc_h264.c b/libavcodec/amfenc_h264.c
index e01da06aa6..78bd70eb7a 100644
--- a/libavcodec/amfenc_h264.c
+++ b/libavcodec/amfenc_h264.c
@@ -110,6 +110,9 @@ static const AVOption options[] = {
     /// Header Insertion Spacing
     { "header_spacing", "Header Insertion Spacing",             OFFSET(header_spacing),     AV_OPT_TYPE_INT, { .i64 = -1 }, -1, 1000, VE },
 
+    /// Maximum queued frames
+    { "async_depth",    "Set maximum encoding parallelism. Higher values increase output latency.", OFFSET(hwsurfaces_in_queue_max), AV_OPT_TYPE_INT, {.i64 = 16 }, 1, 16, VE },
+
     /// B-Frames
     // BPicturesPattern=bf
     { "bf_delta_qp",    "B-Picture Delta QP",                   OFFSET(b_frame_delta_qp),   AV_OPT_TYPE_INT,  { .i64 = 4 }, -10, 10, VE },
diff --git a/libavcodec/amfenc_hevc.c b/libavcodec/amfenc_hevc.c
index 248581bd33..0907db945c 100644
--- a/libavcodec/amfenc_hevc.c
+++ b/libavcodec/amfenc_hevc.c
@@ -83,6 +83,8 @@ static const AVOption options[] = {
     { "gop",            "", 0, AV_OPT_TYPE_CONST, { .i64 = AMF_VIDEO_ENCODER_HEVC_HEADER_INSERTION_MODE_GOP_ALIGNED }, 0, 0, VE, .unit = "hdrmode" },
     { "idr",            "", 0, AV_OPT_TYPE_CONST, { .i64 = AMF_VIDEO_ENCODER_HEVC_HEADER_INSERTION_MODE_IDR_ALIGNED }, 0, 0, VE, .unit = "hdrmode" },
 
+    { "async_depth",    "Set maximum encoding parallelism. Higher values increase output latency.", OFFSET(hwsurfaces_in_queue_max), AV_OPT_TYPE_INT, {.i64 = 16 }, 1, 16, VE },
+
     { "high_motion_quality_boost_enable",   "Enable High motion quality boost mode",  OFFSET(hw_high_motion_quality_boost), AV_OPT_TYPE_BOOL,   {.i64 = -1 }, -1, 1, VE },
     { "gops_per_idr",   "GOPs per IDR 0-no IDR will be inserted",   OFFSET(gops_per_idr),  AV_OPT_TYPE_INT,  { .i64 = 1  },  0, INT_MAX, VE },
     { "preencode",      "Enable preencode",                         OFFSET(preencode),     AV_OPT_TYPE_BOOL, { .i64 = -1  },  -1, 1, VE},