[FFmpeg-devel] [PATCH v5 04/10] cbs_h2645: refact, allow INVALID_OFFSET for id_offset and active_offset

[Nuo Mi]

---
 libavcodec/cbs_h2645.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/libavcodec/cbs_h2645.c b/libavcodec/cbs_h2645.c
index 36212d1da6..fdc527f8e8 100644
--- a/libavcodec/cbs_h2645.c
+++ b/libavcodec/cbs_h2645.c
@@ -664,6 +664,7 @@ static int cbs_h2645_split_fragment(CodedBitstreamContext *ctx,
 static int cbs_h2645_replace_ps(CodedBitstreamContext *ctx,
                                 CodedBitstreamUnit *unit)
 {
+    static const size_t INVALID_OFFSET = (size_t)-1;
     typedef struct {
         int nal_unit_type;
         int max_count;
@@ -728,8 +729,8 @@ static int cbs_h2645_replace_ps(CodedBitstreamContext *ctx,
     const PSType *ps_type;
     AVBufferRef **ref_array;
     void **ptr_array;
-    void **active;
-    int err, id, i, nb_ps_types;
+    void **active = NULL;
+    int err, id = 0, i, nb_ps_types;
 
     switch (ctx->codec->codec_id) {
     case AV_CODEC_ID_H264:
@@ -751,12 +752,14 @@ static int cbs_h2645_replace_ps(CodedBitstreamContext *ctx,
     }
     av_assert0(i < nb_ps_types);
 
-    id = *((uint8_t*)unit->content + ps_type->id_offset);
+    if (ps_type->id_offset != INVALID_OFFSET) {
+        id = *((uint8_t*)unit->content + ps_type->id_offset);
 
-    if (id >= ps_type->max_count) {
-        av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid %s id: %d.\n",
-               ps_type->name, id);
-        return AVERROR_INVALIDDATA;
+        if (id >= ps_type->max_count) {
+            av_log(ctx->log_ctx, AV_LOG_ERROR, "Invalid %s id: %d.\n",
+                ps_type->name, id);
+            return AVERROR_INVALIDDATA;
+        }
     }
 
     err = ff_cbs_make_unit_refcounted(ctx, unit);
@@ -766,9 +769,10 @@ static int cbs_h2645_replace_ps(CodedBitstreamContext *ctx,
     ref_array =
          (AVBufferRef**)((uint8_t*)ctx->priv_data + ps_type->ref_array_offset);
     ptr_array = (void**)((uint8_t*)ctx->priv_data + ps_type->ptr_array_offset);
-    active    = (void**)((uint8_t*)ctx->priv_data + ps_type->active_offset);
+    if (ps_type->active_offset != INVALID_OFFSET)
+        active = (void**)((uint8_t*)ctx->priv_data + ps_type->active_offset);
 
-    if (ptr_array[id] == *active) {
+    if (active && ptr_array[id] == *active) {
         // The old active parameter set is being overwritten, so it can't
         // be active after this point.
         *active = NULL;
-- 
2.25.1