avcodec/hevc: Rewrite scalability_mask_flag parse in decode_vps_ext

Remove a for loop and make it easy to extend to support other types of scalability. Move ScalabilityMask to hevc header file so it can be used in hevc decoder.

Zhao Zhili committed 1 year ago

Commit d3220ed1 parent 01f74bf3 files · +24 −18Browse files

Unified · Split

3 files

libavcodec/hevc/hevc.h +7 −0
libavcodec/hevc/ps.c +15 −18
libavcodec/hevc/ps.h +2 −0

libavcodec/hevc/hevc.h+7−0

@@ -162,5 +162,12 @@ enum { · 161 unmodified lines
162	HEVC_MAX_PALETTE_PREDICTOR_SIZE = 128,	162	HEVC_MAX_PALETTE_PREDICTOR_SIZE = 128,
163	};	163	};
164		164
		165	enum HEVCScalabilityMask {
		166	HEVC_SCALABILITY_DEPTH = 1 << (15 - 0),
		167	HEVC_SCALABILITY_MULTIVIEW = 1 << (15 - 1),
		168	HEVC_SCALABILITY_SPATIAL = 1 << (15 - 2),
		169	HEVC_SCALABILITY_AUXILIARY = 1 << (15 - 3),
		170	HEVC_SCALABILITY_MASK_MAX = 0xFFFF,
		171	};
165		172
166	#endif /* AVCODEC_HEVC_HEVC_H */	173	#endif /* AVCODEC_HEVC_HEVC_H */

libavcodec/hevc/ps.c+15−18

     av_freep(&vps->data);
 }
-enum ScalabilityMask {
-    HEVC_SCALABILITY_DEPTH      = 0,
-    HEVC_SCALABILITY_MULTIVIEW  = 1,
-    HEVC_SCALABILITY_SPATIAL    = 2,
-    HEVC_SCALABILITY_AUXILIARY  = 3,
-    HEVC_SCALABILITY_MASK_MAX   = 15,
-};
 enum DependencyType {
     HEVC_DEP_TYPE_SAMPLE = 0,
     HEVC_DEP_TYPE_MV     = 1,
         return AVERROR_INVALIDDATA;
     splitting_flag = get_bits1(gb);
-    num_scalability_types = 0;
+    vps->scalability_mask_flag = get_bits(gb, 16);
-    for (int i = 0; i <= HEVC_SCALABILITY_MASK_MAX; i++) {
+    num_scalability_types = av_popcount(vps->scalability_mask_flag);
-        int scalability_mask_flag = get_bits1(gb);
+    if (!num_scalability_types) {
-        if (scalability_mask_flag && (i != HEVC_SCALABILITY_MULTIVIEW)) {
+        av_log(avctx, AV_LOG_ERROR, "Missing scalability mask\n");
-            av_log(avctx, AV_LOG_ERROR, "Scalability type %d not supported\n", i);
-            return AVERROR_PATCHWELCOME;
-        }
-        num_scalability_types += scalability_mask_flag;
-    }
-    if (num_scalability_types != 1)
         return AVERROR_INVALIDDATA;
+    } else if (num_scalability_types > 1) {
+        av_log(avctx, AV_LOG_ERROR, "Scalability number %d not supported\n",
+               num_scalability_types);
+        return AVERROR_PATCHWELCOME;
+    }
+    if (!(vps->scalability_mask_flag & HEVC_SCALABILITY_MULTIVIEW)) {
+        av_log(avctx, AV_LOG_ERROR, "Scalability type %d not supported\n",
+               15 - ff_ctz(vps->scalability_mask_flag));
+        return AVERROR_PATCHWELCOME;
+    }
     if (!splitting_flag)
         dimension_id_len = get_bits(gb, 3) + 1;

libavcodec/hevc/ps.h+2−0

@@ -205,6 +205,8 @@ typedef struct HEVCVPS { · 204 unmodified lines
205	*/	205	*/
206	int nb_layers;	206	int nb_layers;
207		207
		208	uint16_t scalability_mask_flag;
		209
208	// LayerIdxInVps[nuh_layer_id], i.e. a mapping of nuh_layer_id to VPS layer	210	// LayerIdxInVps[nuh_layer_id], i.e. a mapping of nuh_layer_id to VPS layer
209	// indices. Valid values are between 0 and HEVC_VPS_MAX_LAYERS. Entries for	211	// indices. Valid values are between 0 and HEVC_VPS_MAX_LAYERS. Entries for
210	// unmapped values of nuh_layer_id are set to -1.	212	// unmapped values of nuh_layer_id are set to -1.

avcodec/hevc: Rewrite scalability_mask_flag parse in decode_vps_ext

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