fix: amf write date

Author: ireader

libflv/include/flv-proto.h

@@ -20,11 +20,11 @@
 #define FLV_AUDIO_AAC		(10 << 4)
 #define FLV_AUDIO_SPEEX		(11 << 4)
 #define FLV_AUDIO_AC3		(12 << 4) // enhanced rtmp v2
-#define FLV_AUDIO_OPUS		(13 << 4)
+#define FLV_AUDIO_OPUS		(13 << 4) // opus-codec.org
 #define FLV_AUDIO_MP3_8K	(14 << 4) // MP3 8 kHz
 #define FLV_AUDIO_DEVIDE	(15 << 4) // Device-specific sound
 #define FLV_AUDIO_ASC		(0x1000 | FLV_AUDIO_AAC)	// AudioSpecificConfig(ISO-14496-3)
-#define FLV_AUDIO_OPUS_HEAD	(0x1100 | FLV_AUDIO_OPUS)	// opus-codec.org
+#define FLV_AUDIO_OPUS_HEAD	(0x1100 | FLV_AUDIO_OPUS)	// https://datatracker.ietf.org/doc/html/rfc7845#section-5.1
 #define FLV_AUDIO_FLAC_HEAD (0x1200 | FLV_AUDIO_FLAC)	// xiph.org/flac
 
 // FLV Video Type

libflv/include/opus-head.h

@@ -21,6 +21,7 @@ struct opus_head_t
     uint8_t channel_mapping[8];
 };
 
+/// @param[out] data https://datatracker.ietf.org/doc/html/rfc7845#section-5.1
 /// @return >0-ok, <=0-error
 int opus_head_save(const struct opus_head_t* opus, uint8_t* data, size_t bytes);
 /// @return >0-ok, <=0-error

libflv/source/amf0.c

@@ -153,7 +153,7 @@ uint8_t* AMFWriteDate(uint8_t* ptr, const uint8_t* end, double milliseconds, int
 
     AMFWriteDouble(ptr, end, milliseconds);
     *ptr = AMF_DATE; // rewrite to date
-    return AMFWriteInt16(ptr + 8, end, timezone);
+    return AMFWriteInt16(ptr + 9, end, timezone);
 }
 
 uint8_t* AMFWriteNamedBoolean(uint8_t* ptr, const uint8_t* end, const char* name, size_t length, uint8_t value)

libflv/source/opus-head.c

@@ -3,6 +3,7 @@
 #include <string.h>
 #include <assert.h>
 
+// https://datatracker.ietf.org/doc/html/rfc7845#section-5.1
 // http://www.opus-codec.org/docs/opus_in_isobmff.html
 // 4.3.2 Opus Specific Box
 /*