ref: 3d48cc60ccf907122be66a241de799a1f9d15cce
parent: 17acb8ae08eec813d4ad6cab36d5dd62a0eeeecd
author: Jean-Marc Valin <jmvalin@jmvalin.ca>
date: Mon Apr 24 20:52:41 EDT 2017
Add header code from opus-tools
--- a/src/opus_header.c
+++ b/src/opus_header.c
@@ -156,6 +156,102 @@
return p.pos;
}
+/*
+ Comments will be stored in the Vorbis style.
+ It is described in the "Structure" section of
+ http://www.xiph.org/ogg/vorbis/doc/v-comment.html
+
+ However, Opus and other non-vorbis formats omit the "framing_bit".
+
+The comment header is decoded as follows:
+ 1) [vendor_length] = read an unsigned integer of 32 bits
+ 2) [vendor_string] = read a UTF-8 vector as [vendor_length] octets
+ 3) [user_comment_list_length] = read an unsigned integer of 32 bits
+ 4) iterate [user_comment_list_length] times {+ 5) [length] = read an unsigned integer of 32 bits
+ 6) this iteration's user comment = read a UTF-8 vector as [length] octets
+ }
+ 7) done.
+*/
+
+#define readint(buf, base) (((buf[base+3]<<24)&0xff000000)| \
+ ((buf[base+2]<<16)&0xff0000)| \
+ ((buf[base+1]<<8)&0xff00)| \
+ (buf[base]&0xff))
+#define writeint(buf, base, val) do{ buf[base+3]=((val)>>24)&0xff; \+ buf[base+2]=((val)>>16)&0xff; \
+ buf[base+1]=((val)>>8)&0xff; \
+ buf[base]=(val)&0xff; \
+ }while(0)
+
+void comment_init(char **comments, int* length, const char *vendor_string)
+{+ /*The 'vendor' field should be the actual encoding library used.*/
+ int vendor_length=strlen(vendor_string);
+ int user_comment_list_length=0;
+ int len=8+4+vendor_length+4;
+ char *p=(char*)malloc(len);
+ if(p==NULL){+ fprintf(stderr, "malloc failed in comment_init()\n");
+ exit(1);
+ }
+ memcpy(p, "OpusTags", 8);
+ writeint(p, 8, vendor_length);
+ memcpy(p+12, vendor_string, vendor_length);
+ writeint(p, 12+vendor_length, user_comment_list_length);
+ *length=len;
+ *comments=p;
+}
+
+void comment_add(char **comments, int* length, char *tag, char *val)
+{+ char* p=*comments;
+ int vendor_length=readint(p, 8);
+ int user_comment_list_length=readint(p, 8+4+vendor_length);
+ int tag_len=(tag?strlen(tag)+1:0);
+ int val_len=strlen(val);
+ int len=(*length)+4+tag_len+val_len;
+
+ p=(char*)realloc(p, len);
+ if(p==NULL){+ fprintf(stderr, "realloc failed in comment_add()\n");
+ exit(1);
+ }
+
+ writeint(p, *length, tag_len+val_len); /* length of comment */
+ if(tag){+ memcpy(p+*length+4, tag, tag_len); /* comment tag */
+ (p+*length+4)[tag_len-1] = '='; /* separator */
+ }
+ memcpy(p+*length+4+tag_len, val, val_len); /* comment */
+ writeint(p, 8+4+vendor_length, user_comment_list_length+1);
+ *comments=p;
+ *length=len;
+}
+
+void comment_pad(char **comments, int* length, int amount)
+{+ if(amount>0){+ int i;
+ int newlen;
+ char* p=*comments;
+ /*Make sure there is at least amount worth of padding free, and
+ round up to the maximum that fits in the current ogg segments.*/
+ newlen=(*length+amount+255)/255*255-1;
+ p=realloc(p,newlen);
+ if(p==NULL){+ fprintf(stderr,"realloc failed in comment_pad()\n");
+ exit(1);
+ }
+ for(i=*length;i<newlen;i++)p[i]=0;
+ *comments=p;
+ *length=newlen;
+ }
+}
+#undef readint
+#undef writeint
+
+
/* This is just here because it's a convenient file linked by both opusenc and
opusdec (to guarantee this maps stays in sync). */
const int wav_permute_matrix[8][8] =
--- a/src/opus_header.h
+++ b/src/opus_header.h
@@ -28,6 +28,7 @@
#ifndef OPUS_HEADER_H
#define OPUS_HEADER_H
+#include <stdlib.h>
#include <ogg/ogg.h>
typedef struct {@@ -46,5 +47,11 @@
int opus_header_to_packet(const OpusHeader *h, unsigned char *packet, int len);
extern const int wav_permute_matrix[8][8];
+
+void comment_init(char **comments, int* length, const char *vendor_string);
+
+void comment_add(char **comments, int* length, char *tag, char *val);
+
+void comment_pad(char **comments, int* length, int amount);
#endif