[FFmpeg-devel] [PATCH] avfilter/vf_amf_common: implement reset_sar options

Timo Rothenpieler timo at rothenpieler.org
Mon Feb 10 15:34:38 EET 2025


Implements the new reset_sar option from a28dc06869fe1f98c07e42f9b0a411d2744ff7d7.

While at it, this also moves assigning the output sar on the outlink
from the filter frame function to config props.
---
 libavfilter/vf_amf_common.c | 18 ++++++++++++------
 libavfilter/vf_amf_common.h |  1 +
 libavfilter/vf_vpp_amf.c    |  5 +++--
 3 files changed, 16 insertions(+), 8 deletions(-)

diff --git a/libavfilter/vf_amf_common.c b/libavfilter/vf_amf_common.c
index fbf364eac1..75339c9f01 100644
--- a/libavfilter/vf_amf_common.c
+++ b/libavfilter/vf_amf_common.c
@@ -158,11 +158,6 @@ int amf_filter_filter_frame(AVFilterLink *inlink, AVFrame *in)
         goto fail;
     }
 
-    if (inlink->sample_aspect_ratio.num) {
-        outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
-    } else
-        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
-
     av_frame_free(&in);
     return ff_filter_frame(outlink, out);
 fail:
@@ -274,6 +269,7 @@ int amf_init_filter_config(AVFilterLink *outlink, enum AVPixelFormat *in_format)
     enum AVPixelFormat out_sw_format = ctx->format;
     FilterLink        *inl = ff_filter_link(inlink);
     FilterLink        *outl = ff_filter_link(outlink);
+    double w_adj = 1.0;
 
     if ((err = ff_scale_eval_dimensions(avctx,
                                         ctx->w_expr, ctx->h_expr,
@@ -281,8 +277,11 @@ int amf_init_filter_config(AVFilterLink *outlink, enum AVPixelFormat *in_format)
                                         &ctx->width, &ctx->height)) < 0)
         return err;
 
+    if (ctx->reset_sar && inlink->sample_aspect_ratio.num)
+        w_adj = (double)inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den;
+
     ff_scale_adjust_dimensions(inlink, &ctx->width, &ctx->height,
-                               ctx->force_original_aspect_ratio, ctx->force_divisible_by, 1.0);
+                               ctx->force_original_aspect_ratio, ctx->force_divisible_by, w_adj);
 
     av_buffer_unref(&ctx->amf_device_ref);
     av_buffer_unref(&ctx->hwframes_in_ref);
@@ -343,6 +342,13 @@ int amf_init_filter_config(AVFilterLink *outlink, enum AVPixelFormat *in_format)
     outlink->w = ctx->width;
     outlink->h = ctx->height;
 
+    if (ctx->reset_sar)
+        outlink->sample_aspect_ratio = (AVRational){1, 1};
+    else if (inlink->sample_aspect_ratio.num)
+        outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h * inlink->w, outlink->w * inlink->h}, inlink->sample_aspect_ratio);
+    else
+        outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
+
     hwframes_out->width = outlink->w;
     hwframes_out->height = outlink->h;
 
diff --git a/libavfilter/vf_amf_common.h b/libavfilter/vf_amf_common.h
index c4b5ba659a..d0a0214978 100644
--- a/libavfilter/vf_amf_common.h
+++ b/libavfilter/vf_amf_common.h
@@ -48,6 +48,7 @@ typedef struct AMFFilterContext {
     char *format_str;
     int force_original_aspect_ratio;
     int force_divisible_by;
+    int reset_sar;
 
     AMFComponent        *component;
     AVBufferRef         *amf_device_ref;
diff --git a/libavfilter/vf_vpp_amf.c b/libavfilter/vf_vpp_amf.c
index 87bd68074f..2d9df50632 100644
--- a/libavfilter/vf_vpp_amf.c
+++ b/libavfilter/vf_vpp_amf.c
@@ -216,11 +216,12 @@ static const AVOption vpp_amf_options[] = {
     { "smpte428",       "SMPTE428",                 0,  AV_OPT_TYPE_CONST, { .i64 = AMF_COLOR_TRANSFER_CHARACTERISTIC_SMPTE428 }, 0, 0, FLAGS, "trc" },
     { "arib-std-b67",   "ARIB_STD_B67",             0,  AV_OPT_TYPE_CONST, { .i64 = AMF_COLOR_TRANSFER_CHARACTERISTIC_ARIB_STD_B67 }, 0, 0, FLAGS, "trc" },
 
-    { "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0}, 0, 2, FLAGS, "force_oar" },
+    { "force_original_aspect_ratio", "decrease or increase w/h if necessary to keep the original AR", OFFSET(force_original_aspect_ratio), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 2, FLAGS, "force_oar" },
     { "disable",  NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0 }, 0, 0, FLAGS, "force_oar" },
     { "decrease", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1 }, 0, 0, FLAGS, "force_oar" },
     { "increase", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 2 }, 0, 0, FLAGS, "force_oar" },
-    { "force_divisible_by", "enforce that the output resolution is divisible by a defined integer when force_original_aspect_ratio is used", OFFSET(force_divisible_by), AV_OPT_TYPE_INT, { .i64 = 1}, 1, 256, FLAGS },
+    { "force_divisible_by", "enforce that the output resolution is divisible by a defined integer when force_original_aspect_ratio is used", OFFSET(force_divisible_by), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, 256, FLAGS },
+    { "reset_sar", "reset SAR to 1 and scale to square pixels if scaling proportionally", OFFSET(reset_sar), AV_OPT_TYPE_BOOL, { .i64 = 0 }, 0, 1, FLAGS },
 
     { NULL },
 };
-- 
2.43.0



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