mika/libnx
1
0
Fork 0
mirror of https://github.com/switchbrew/libnx.git synced 2025-06-26 06:42:47 +02:00
Code Issues Packages Projects Releases Wiki Activity

hwopus: Document second member of HwopusHeader

Browse Source 
This second member indicates the Opus encoder's entropy coder's final
range. While nothing in the service actually does anything with the
final range as far as I can tell, this is specified within RFC 6716
(https://tools.ietf.org/html/rfc6716, see section "6. Conformance") as a
means of ensuring decoder conformance. States as follows:

"In addition, a compliant decoder implementation MUST have
 the same final range decoder state as that of the reference decoder."

So what is likely done when performing compliance testing is the data is
encoded, and then the final range of the encoder is sent via this
header, then during decoding, the final range would be checked against
to ensure that it's valid.
This commit is contained in:
Lioncash 2019-03-10 20:56:38 -04:00 committed by yellows8
parent ef370fd33a
commit 03143cbadc
1 changed files with 2 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
nx/include/switch/services/hwopus.h
View File

@ -18,8 +18,8 @@ typedef struct {
/// This structure is the start of opusin for \ref hwopusDecodeInterleaved, with the actual opus packet following this.
/// These fields are big-endian.
typedef struct {
u32 size; ///< Size of the packet following this header.
u32 unk; ///< Unknown, can be left at zero.
u32 size; ///< Size of the packet following this header.
u32 final_range; ///< Indicates the final range of the codec encoder's entropy coder. This can be left at zero.
} HwopusHeader;
/// Used internally.