shithub: opus-tools

Download patch

ref: 35c4fb886146b374adfddde63c8c35505eb2be99
parent: 22f60eeda82c051ea8844f3be02da44e860ec7eb
author: Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>
date: Sun Jul 31 17:54:59 EDT 2011 

Header handlign code (completely untested)


--- a/src/opus_header.c
+++ b/src/opus_header.c
@@ -1,11 +1,139 @@
 #include "opus_header.h"
+#include <string.h>
 
-void opus_header_parse(const unsigned char *header, OpusHeader *h)
+/* Header contents:
+  - "OpusHead" (64 bits)
+  - Sampling rate (32 bits, max 192)
+  - Channel mapping (bool in byte)
+  - Channels (8 bits)
+  - Pre-gap (16 bits)
+*/
+
+typedef struct {
+   unsigned char *data;
+   int maxlen;
+   int pos;
+} Packet;
+
+typedef struct {
+   const unsigned char *data;
+   int maxlen;
+   int pos;
+} ROPacket;
+
+static int write_uint32(Packet *p, opus_uint32 val)
 {
+   if (p->pos>p->maxlen-4)
+      return 0;
+   p->data[p->pos  ] = (val>>24) & 0xFF;
+   p->data[p->pos+1] = (val>>16) & 0xFF;
+   p->data[p->pos+2] = (val>> 8) & 0xFF;
+   p->data[p->pos+3] = (val    ) & 0xFF;
+   p->pos += 4;
+   return 1;
 }
 
+static int write_uint16(Packet *p, opus_uint16 val)
+{
+   if (p->pos>p->maxlen-4)
+      return 0;
+   p->data[p->pos  ] = (val>> 8) & 0xFF;
+   p->data[p->pos+1] = (val    ) & 0xFF;
+   p->pos += 2;
+   return 1;
+}
+
+static int write_chars(Packet *p, const unsigned char *str, int nb_chars)
+{
+   int i;
+   if (p->pos>p->maxlen-nb_chars)
+      return 0;
+   for (i=0;i<nb_chars;i++)
+      p->data[p->pos++] = str[i];
+   return 1;
+}
+
+static int read_uint32(ROPacket *p, opus_uint32 *val)
+{
+   if (p->pos>p->maxlen-4)
+      return 0;
+   *val =  (opus_uint32)p->data[p->pos  ]<<24;
+   *val |= (opus_uint32)p->data[p->pos+1]<<16;
+   *val |= (opus_uint32)p->data[p->pos+2]<< 8;
+   *val |= (opus_uint32)p->data[p->pos+3];
+   p->pos += 4;
+   return 1;
+}
+
+static int read_uint16(ROPacket *p, opus_uint16 *val)
+{
+   if (p->pos>p->maxlen-4)
+      return 0;
+   *val =  (opus_uint16)p->data[p->pos  ]<<8;
+   *val |= (opus_uint16)p->data[p->pos+1];
+   p->pos += 4;
+   return 1;
+}
+
+static int read_chars(ROPacket *p, unsigned char *str, int nb_chars)
+{
+   int i;
+   if (p->pos>p->maxlen-nb_chars)
+      return 0;
+   for (i=0;i<nb_chars;i++)
+      str[i] = p->data[p->pos++];
+   return 1;
+}
+
+int opus_header_parse(const unsigned char *packet, int len, OpusHeader *h)
+{
+   char str[9];
+   ROPacket p;
+   unsigned char ch;
+   opus_uint16 shortval;
+   
+   p.data = packet;
+   p.maxlen = len;
+   p.pos = 0;
+   str[8] = 0;
+   read_chars(&p, (unsigned char*)str, 8);
+   if (strcmp(str, "OpusHead")!=0)
+      return 0;
+   if (!read_uint32(&p, &h->sample_rate))
+      return 0;
+   if (!read_chars(&p, &ch, 1))
+      return 0;
+   h->multi_stream = ch;
+   if (!read_chars(&p, &ch, 1))
+      return 0;
+   h->channels = ch;
+   if (!read_uint16(&p, &shortval))
+      return 0;
+   h->pregap = shortval;
+   
+   return 1;
+}
+
 int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len)
 {
-   return len;
+   Packet p;
+   unsigned char ch;
+   
+   p.data = packet;
+   p.maxlen = len;
+   p.pos = 0;
+   if (!write_chars(&p, (const unsigned char*)"OpusHead", 8))
+      return 0;
+   if (!write_uint32(&p, h->sample_rate))
+      return 0;
+   ch = h->multi_stream;
+   if (!write_chars(&p, &ch, 1))
+      return 0;
+   ch = h->channels;
+   if (!write_chars(&p, &ch, 1))
+      return 0;
+   if (!write_uint16(&p, h->pregap))
+      return 0;
+   return p.pos;
 }
 
--- a/src/opus_header.h
+++ b/src/opus_header.h
@@ -1,8 +1,10 @@
 #ifndef OPUS_HEADER_H
 #define OPUS_HEADER_H
 
+#include "opus_types.h"
+
 typedef struct {
-   int sample_rate;
+   opus_uint32 sample_rate;
    int multi_stream;
    int channels;
    int pregap;
@@ -9,7 +11,7 @@
    unsigned char mapping[256][3];
 } OpusHeader;
 
-void opus_header_parse(const unsigned char *header, OpusHeader *h);
+int opus_header_parse(const unsigned char *header, int len, OpusHeader *h);
 int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len);
 
 #endif
--- a/src/opusenc.c
+++ b/src/opusenc.c
@@ -429,7 +429,10 @@
    comment_init(&comments, &comments_length, vendor_string);
 
    header.channels = chan;
-
+   header.pregap = 0;
+   header.multi_stream = 0;
+   header.sample_rate = rate;
+   
    {
       char *st_string="mono";
       if (chan==2)