commit b27d5044776c7ce38d11024db5867e5b4735498a
author Marco Paniconi <marpan@google.com> Thu Oct 09 08:41:42 2025 -0700
committer Marco Paniconi <marpan@google.com> Mon Oct 13 17:00:57 2025 -0700
tree 23cac39b1c9f57a5f033766e79b9fdfec3d702e7
parent 07ef372dcd38e0b72a3f2b0e936038408817403b

Disable svc for lag_in_frames > 0 in good_quality mode

SVC for nonzero lag_in_frames in good_quality mode is
not currently supported/tested.

This previous patch allows for it, but it was not merged in:
https://aomedia-review.googlesource.com/c/aom/+/193401

So for now disable the usage under these conditions.

Added unittest that reproduces the issue.

Bug: b:449376308
Change-Id: Ieacf306bf6e4d51bf3330fe0ead56dc85a7e1a75

av1/av1_cx_iface.c

diff --git a/av1/av1_cx_iface.c b/av1/av1_cx_iface.c
index 295ff0d..89d9b92 100644
--- a/av1/av1_cx_iface.c
+++ b/av1/av1_cx_iface.c
@@ -4011,6 +4011,8 @@
 
   if (ppi->number_spatial_layers > 1 || ppi->number_temporal_layers > 1) {
     unsigned int sl, tl;
+    // Disable svc for lag_in_frames > 0.
+    if (cpi->oxcf.gf_cfg.lag_in_frames > 0) return AOM_CODEC_INVALID_PARAM;
     ctx->ppi->use_svc = 1;
     const int num_layers =
         ppi->number_spatial_layers * ppi->number_temporal_layers;

test/encode_api_test.cc

diff --git a/test/encode_api_test.cc b/test/encode_api_test.cc
index 858bf46..3bf2205 100644
--- a/test/encode_api_test.cc
+++ b/test/encode_api_test.cc
@@ -1645,4 +1645,44 @@
   ASSERT_EQ(aom_codec_destroy(&enc), AOM_CODEC_OK);
 }
 
+// This test is based on the issue:449376308. The segfault in
+// av1_update_layer_context_change_config() is triggered
+// by doing svc with nonzero lag_in_frames and good_quality usage.
+// Note good_quality mode is needed because for realtime mode lag_in_frames
+// is forced to 0 in set_encoder_config() .
+TEST(EncodeAPI, Issue449376308) {
+  aom_codec_iface_t *iface = aom_codec_av1_cx();
+  aom_codec_enc_cfg_t cfg;
+  ASSERT_EQ(aom_codec_enc_config_default(iface, &cfg, AOM_USAGE_GOOD_QUALITY),
+            AOM_CODEC_OK);
+  cfg.g_w = 320;
+  cfg.g_h = 240;
+  cfg.g_timebase.num = 1;
+  cfg.g_timebase.den = 30;
+  cfg.rc_target_bitrate = 1000;
+  cfg.g_lag_in_frames = 25;
+  aom_codec_ctx_t enc;
+  ASSERT_EQ(aom_codec_enc_init(&enc, iface, &cfg, 0), AOM_CODEC_OK);
+  // AV1E_SET_SVC_PARAMS
+  aom_svc_params_t svc_params = {};
+  svc_params.number_spatial_layers = 3;
+  svc_params.number_temporal_layers = 2;
+  for (int i = 0; i < AOM_MAX_LAYERS; i++) {
+    svc_params.max_quantizers[i] = 30;
+    svc_params.min_quantizers[i] = 0;
+    svc_params.layer_target_bitrate[i] = 1000;
+  }
+  for (int i = 0; i < AOM_MAX_SS_LAYERS; i++) {
+    svc_params.scaling_factor_num[i] = 1;
+    svc_params.scaling_factor_den[i] = 1;
+  }
+  for (int i = 0; i < AOM_MAX_TS_LAYERS; i++) {
+    svc_params.framerate_factor[i] = 1;
+  }
+  // set_svc_params should fail since lag_in_frames > 0.
+  EXPECT_NE(aom_codec_control(&enc, AV1E_SET_SVC_PARAMS, &svc_params),
+            AOM_CODEC_OK);
+  ASSERT_EQ(aom_codec_destroy(&enc), AOM_CODEC_OK);
+}
+
 }  // namespace