X-Git-Url: http://git.tuebingen.mpg.de/?p=paraslash.git;a=blobdiff_plain;f=udp_header.h;h=83157e6ba1974fcad3453a45d1873b899335e44b;hp=24f6bb87d3a411b57984c8bbea1a1d2d1f3e4e36;hb=9627e8157c8c916555b993d7254b0b638815ebc1;hpb=9692b4241bc316665bd5b6810ea8af83057a0a89

diff --git a/udp_header.h b/udp_header.h
index 24f6bb87..83157e6b 100644
--- a/udp_header.h
+++ b/udp_header.h
@@ -13,14 +13,16 @@
  * this header, the type of the current audio stream and the * type of this
  * data chunk is coded.
  */
-#define UDP_AUDIO_HEADER_LEN 8
+#define UDP_AUDIO_HEADER_LEN 16
 
 /** The possible stream types. */
 enum udp_stream_type {
 	/** Used for mp3 and aac streams. */
 	UDP_PLAIN_STREAM,
-	/* Ogg vorbis streams. */
-	UDP_HEADER_STREAM
+	/** Ogg vorbis streams. */
+	UDP_HEADER_STREAM,
+	/** stream type not yet known. */
+	UDP_UNKNOWN_STREAM
 };
 
 /** The possible packet types. */
@@ -32,106 +34,66 @@ enum udp_audio_packet_type {
 	/** Combined header/data packet (ogg only). */
 	UDP_HEADER_PACKET,
 	/** Packet contains only audio file data. */
-	UDP_DATA_PACKET
+	UDP_DATA_PACKET,
+	/** Invalid packet type. */
+	UDP_UNKNOWN_PACKET
+};
+
+/** The contents of an udp audio header. */
+struct udp_audio_header {
+	/** see \ref udp_stream_type. */
+	uint8_t stream_type;
+	/** see \ref udp_audio_packet_type. */
+	uint8_t packet_type;
+	/** Non-zero only for header packets. */
+	uint16_t header_len;
+	/** Length of header plus audio file data. */
+	uint16_t payload_len;
 };
 
 /**
- * Write the magic bytes to the beginning of a buffer.
+ * Write a struct udp_audio_header to a buffer.
+ *
+ * \param buf The buffer to write to.
+ * \param h The audio header to write.
+ *
+ * Used by the udp sender.
  *
- * \param buf The buffer.
  */
-_static_inline_ void udp_write_magic(char *buf)
+_static_inline_ void write_udp_audio_header(char *buf, struct udp_audio_header *h)
 {
 	memcpy(buf, "UDPM", 4);
+	write_u8(buf + 4, h->stream_type);
+	write_u8(buf + 5, h->packet_type);
+	write_u16(buf + 6, h->header_len);
+	write_u16(buf + 8, h->payload_len);
+	memset(buf + 10, 0, 6);
 }
 
 /**
- * Check whether this buffer contains the magic bytes.
+ * Used by the udp receiver to read a struct udp_audio_header from a buffer.
  *
- * \param buf The buffer.
- * \param len The number of bytes of \a buf.
+ * \param buf The buffer to read from.
+ * \param len The length of \a buf.
+ * \param h Result pointer.
  *
- * \return Positive if \a buf contains the magic bytes,
- * -1 otherwise.
+ * \return 1 if \a buf contains a valid udp audio header, -1 else.
  */
-_static_inline_ int udp_check_magic(char *buf, size_t len)
+_static_inline_ int read_udp_audio_header(char *buf, size_t len,
+		struct udp_audio_header *h)
 {
 	if (len < 4)
-		return -1;
+		goto err;
 	if (memcmp(buf, "UDPM", 4))
-		return -1;
+		goto err;
+	h->stream_type = read_u8(buf + 4);
+	h->packet_type = read_u8(buf + 5);
+	h->header_len = read_u16(buf + 6);
+	h->payload_len = read_u16(buf + 8);
 	return 1;
-}
-
-/**
- * Write the type of the audio stream to a buffer.
- *
- * \param buf The buffer.
- * \param type The type to be written.
- *
- * \sa \ref udp_stream_type.
- */
-_static_inline_ void udp_write_stream_type(char *buf, uint8_t type)
-{
-	write_u8(buf + 4, type);
-}
-
-/**
- * Read the type of the audio stream from a buffer.
- *
- * \param buf The buffer.
- *
- * \return Either UDP_PLAIN_STREAM or UDP_HEADER_STREAM.
- * \sa \ref udp_stream_type.
- */
-_static_inline_ uint8_t udp_read_stream_type(char *buf)
-{
-	return read_u8(buf + 4);
-}
-
-/**
- * Write the type of this packet to a buffer.
- *
- * \param buf The buffer.
- * \param type The type to be written.
- *
- * \sa \ref udp_audio_packet_type.
- */
-_static_inline_ void udp_write_packet_type(char *buf, uint8_t type)
-{
-	write_u8(buf + 5, type);
-}
-
-/**
- * Read the type of this buffer.
- *
- * \param buf The buffer.
- *
- * \return The packet type, see \ref udp_stream_type.
- */
-_static_inline_ uint8_t udp_read_packet_type(char *buf)
-{
-	return read_u8(buf + 5);
-}
-
-/**
- * Write the length of the header (non-zero only for ogg streams).
- *
- * \param buf The buffer.
- * \param len The length of the header in bytes.
- */
-_static_inline_ void udp_write_header_len(char *buf, uint16_t len)
-{
-	write_u16(buf + 6, len);
-}
-
-/**
- * Read the length of the header.
- *
- * \param buf The buffer.
- * \return The header length in bytes.
- */
-_static_inline_ uint16_t udp_read_header_len(char *buf)
-{
-	return read_u16(buf + 6);
+err:
+	h->stream_type = UDP_UNKNOWN_STREAM;
+	h->packet_type = UDP_UNKNOWN_PACKET;
+	h->header_len = h->payload_len = 0;
+	return -1;
 }