Fix #657: clarify that trimming is optional

AOMediaCodec · Aug 16, 2023 · 4835365 · 4835365
1 parent 0820e1d
commit 4835365
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/index.bs b/index.bs
@@ -488,7 +488,7 @@ It SHALL always be set to 0 for the following [=obu_type=] values:
 
 If a decoder encounters an OBU with [=obu_redundant_copy=] = 1, and it has also received the previous non-redundant OBU, it MAY ignore the redundant OBU. If the decoder has not received the previous non-redundant OBU, it SHALL treat the redundant copy as a non-redundant OBU and process the OBU accordingly.
 
-<dfn noexport>obu_trimming_status_flag</dfn> indicates whether this OBU has audio samples to be trimmed. It SHALL be set only when [=obu_type=] is set to OBU_IA_Audio_Frame or OBU_IA_Audio_Frame_ID0 to OBU_IA_Audio_Frame_ID17.
+<dfn noexport>obu_trimming_status_flag</dfn> indicates whether this OBU has audio samples to be trimmed. It SHALL be set to 0 or 1 if the [=obu_type=] is set to OBU_IA_Audio_Frame or OBU_IA_Audio_Frame_ID0 to OBU_IA_Audio_Frame_ID17. Otherwise, it SHALL be set to 0.
 
 For a given coded [=Audio Substream=], 
 - If an [=Audio Frame OBU=] has its [=num_samples_to_trim_at_start=] field set to a non-zero value N, the decoder SHALL discard the first N audio samples.