Rewrite mpegts producer and consumer

2023-08-19 16:37:52 +03:00
parent 24039218a1
commit f67f6e5b9f
17 changed files with 993 additions and 1030 deletions
@@ -57,5 +57,45 @@ func ADTSToCodec(b []byte) *core.Codec {

 func ReadADTSSize(b []byte) uint16 {
 	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	_ = b[5] // bounds
 	return uint16(b[3]&0x03)<<(8+3) | uint16(b[4])<<3 | uint16(b[5]>>5)
 }
+
+func WriteADTSSize(b []byte, size uint16) {
+	// AAAAAAAA AAAABCCD EEFFFFGH HHIJKLMM MMMMMMMM MMMOOOOO OOOOOOPP (QQQQQQQQ QQQQQQQQ)
+	_ = b[5] // bounds
+	b[3] |= byte(size >> (8 + 3))
+	b[4] = byte(size >> 3)
+	b[5] |= byte(size << 5)
+	return
+}
+
+func CodecToADTS(codec *core.Codec) []byte {
+	s := core.Between(codec.FmtpLine, "config=", ";")
+	conf, err := hex.DecodeString(s)
+	if err != nil {
+		return nil
+	}
+
+	objType, sampleFreqIdx, channels, _ := DecodeConfig(conf)
+	profile := objType - 1
+
+	wr := bits.NewWriter(nil)
+	wr.WriteAllBits(1, 12)          // Syncword, all bits must be set to 1
+	wr.WriteBit(0)                  // MPEG Version, set to 0 for MPEG-4 and 1 for MPEG-2
+	wr.WriteBits8(0, 2)             // Layer, always set to 0
+	wr.WriteBit(1)                  // Protection absence, set to 1 if there is no CRC and 0 if there is CRC
+	wr.WriteBits8(profile, 2)       // Profile, the MPEG-4 Audio Object Type minus 1
+	wr.WriteBits8(sampleFreqIdx, 4) // MPEG-4 Sampling Frequency Index
+	wr.WriteBit(0)                  // Private bit, guaranteed never to be used by MPEG, set to 0 when encoding, ignore when decoding
+	wr.WriteBits8(channels, 3)      // MPEG-4 Channel Configuration
+	wr.WriteBit(0)                  // Originality, set to 1 to signal originality of the audio and 0 otherwise
+	wr.WriteBit(0)                  // Home, set to 1 to signal home usage of the audio and 0 otherwise
+	wr.WriteBit(0)                  // Copyright ID bit
+	wr.WriteBit(0)                  // Copyright ID start
+	wr.WriteBits16(0, 13)           // Frame length
+	wr.WriteAllBits(1, 11)          // Buffer fullness (variable bitrate)
+	wr.WriteBits8(0, 2)             // Number of AAC frames (Raw Data Blocks) in ADTS frame minus 1
+
+	return wr.Bytes()
+}