ref: 2e1bb011e07d4d67eda9d5a8dd00c0e1682e4b00
dir: /src/picture.c/
/* Copyright (C)2007-2013 Xiph.Org Foundation
File: picture.c
Redistribution and use in source and binary forms, with or without
modification, are permitted provided that the following conditions
are met:
- Redistributions of source code must retain the above copyright
notice, this list of conditions and the following disclaimer.
- Redistributions in binary form must reproduce the above copyright
notice, this list of conditions and the following disclaimer in the
documentation and/or other materials provided with the distribution.
THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR
CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#ifdef HAVE_CONFIG_H
# include "config.h"
#endif
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "picture.h"
static const char BASE64_TABLE[64]={
'A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P',
'Q','R','S','T','U','V','W','X','Y','Z','a','b','c','d','e','f',
'g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v',
'w','x','y','z','0','1','2','3','4','5','6','7','8','9','+','/'
};
/*Utility function for base64 encoding METADATA_BLOCK_PICTURE tags.
Stores BASE64_LENGTH(len)+1 bytes in dst (including a terminating NUL).*/
void base64_encode(char *dst, const char *src, int len){
unsigned s0;
unsigned s1;
unsigned s2;
int ngroups;
int i;
ngroups=len/3;
for(i=0;i<ngroups;i++){
s0=(unsigned char)src[3*i+0];
s1=(unsigned char)src[3*i+1];
s2=(unsigned char)src[3*i+2];
dst[4*i+0]=BASE64_TABLE[s0>>2];
dst[4*i+1]=BASE64_TABLE[(s0&3)<<4|s1>>4];
dst[4*i+2]=BASE64_TABLE[(s1&15)<<2|s2>>6];
dst[4*i+3]=BASE64_TABLE[s2&63];
}
len-=3*i;
if(len==1){
s0=(unsigned char)src[3*i+0];
dst[4*i+0]=BASE64_TABLE[s0>>2];
dst[4*i+1]=BASE64_TABLE[(s0&3)<<4];
dst[4*i+2]='=';
dst[4*i+3]='=';
i++;
}
else if(len==2){
s0=(unsigned char)src[3*i+0];
s1=(unsigned char)src[3*i+1];
dst[4*i+0]=BASE64_TABLE[s0>>2];
dst[4*i+1]=BASE64_TABLE[(s0&3)<<4|s1>>4];
dst[4*i+2]=BASE64_TABLE[(s1&15)<<2];
dst[4*i+3]='=';
i++;
}
dst[4*i]='\0';
}
/*A version of strncasecmp() that is guaranteed to only ignore the case of
ASCII characters.*/
int oi_strncasecmp(const char *a, const char *b, int n){
int i;
for(i=0;i<n;i++){
int aval;
int bval;
int diff;
aval=a[i];
bval=b[i];
if(aval>='a'&&aval<='z') {
aval-='a'-'A';
}
if(bval>='a'&&bval<='z'){
bval-='a'-'A';
}
diff=aval-bval;
if(diff){
return diff;
}
}
return 0;
}
int is_jpeg(const unsigned char *buf, size_t length){
return length>=11&&memcmp(buf,"\xFF\xD8\xFF\xE0",4)==0
&&(buf[4]<<8|buf[5])>=16&&memcmp(buf+6,"JFIF",5)==0;
}
int is_png(const unsigned char *buf, size_t length){
return length>=8&&memcmp(buf,"\x89PNG\x0D\x0A\x1A\x0A",8)==0;
}
int is_gif(const unsigned char *buf, size_t length){
return length>=6
&&(memcmp(buf,"GIF87a",6)==0||memcmp(buf,"GIF89a",6)==0);
}
#define READ_U32_BE(buf) \
(((buf)[0]<<24)|((buf)[1]<<16)|((buf)[2]<<8)|((buf)[3]&0xff))
/*Tries to extract the width, height, bits per pixel, and palette size of a
PNG.
On failure, simply leaves its outputs unmodified.*/
void extract_png_params(const unsigned char *data, size_t data_length,
opus_uint32 *width, opus_uint32 *height,
opus_uint32 *depth, opus_uint32 *colors,
int *has_palette){
if(is_png(data,data_length)){
size_t offs;
offs=8;
while(data_length-offs>=12){
opus_uint32 chunk_len;
chunk_len=READ_U32_BE(data+offs);
if(chunk_len>data_length-(offs+12))break;
else if(chunk_len==13&&memcmp(data+offs+4,"IHDR",4)==0){
int color_type;
*width=READ_U32_BE(data+offs+8);
*height=READ_U32_BE(data+offs+12);
color_type=data[offs+17];
if(color_type==3){
*depth=24;
*has_palette=1;
}
else{
int sample_depth;
sample_depth=data[offs+16];
if(color_type==0)*depth=sample_depth;
else if(color_type==2)*depth=sample_depth*3;
else if(color_type==4)*depth=sample_depth*2;
else if(color_type==6)*depth=sample_depth*4;
*colors=0;
*has_palette=0;
break;
}
}
else if(*has_palette>0&&memcmp(data+offs+4,"PLTE",4)==0){
*colors=chunk_len/3;
break;
}
offs+=12+chunk_len;
}
}
}
/*Tries to extract the width, height, bits per pixel, and palette size of a
GIF.
On failure, simply leaves its outputs unmodified.*/
void extract_gif_params(const unsigned char *data, size_t data_length,
opus_uint32 *width, opus_uint32 *height,
opus_uint32 *depth, opus_uint32 *colors,
int *has_palette){
if(is_gif(data,data_length)&&data_length>=14){
*width=data[6]|data[7]<<8;
*height=data[8]|data[9]<<8;
/*libFLAC hard-codes the depth to 24.*/
*depth=24;
*colors=1<<((data[10]&7)+1);
*has_palette=1;
}
}
/*Tries to extract the width, height, bits per pixel, and palette size of a
JPEG.
On failure, simply leaves its outputs unmodified.*/
void extract_jpeg_params(const unsigned char *data, size_t data_length,
opus_uint32 *width, opus_uint32 *height,
opus_uint32 *depth, opus_uint32 *colors,
int *has_palette){
if(is_jpeg(data,data_length)){
size_t offs;
offs=2;
for(;;){
size_t segment_len;
int marker;
while(offs<data_length&&data[offs]!=0xFF)offs++;
while(offs<data_length&&data[offs]==0xFF)offs++;
marker=data[offs];
offs++;
/*If we hit EOI* (end of image), or another SOI* (start of image),
or SOS (start of scan), then stop now.*/
if(offs>=data_length||(marker>=0xD8&&marker<=0xDA))break;
/*RST* (restart markers): skip (no segment length).*/
else if(marker>=0xD0&&marker<=0xD7)continue;
/*Read the length of the marker segment.*/
if(data_length-offs<2)break;
segment_len=data[offs]<<8|data[offs+1];
if(segment_len<2||data_length-offs<segment_len)break;
if(marker==0xC0||(marker>0xC0&&marker<0xD0&&(marker&3)!=0)){
/*Found a SOFn (start of frame) marker segment:*/
if(segment_len>=8){
*height=data[offs+3]<<8|data[offs+4];
*width=data[offs+5]<<8|data[offs+6];
*depth=data[offs+2]*data[offs+7];
*colors=0;
*has_palette=0;
}
break;
}
/*Other markers: skip the whole marker segment.*/
offs+=segment_len;
}
}
}
#define IMAX(a,b) ((a) > (b) ? (a) : (b))
/*Parse a picture SPECIFICATION as given on the command-line.
spec: The specification.
error_message: Returns an error message on error.
seen_file_icons: Bit flags used to track if any pictures of type 1 or type 2
have already been added, to ensure only one is allowed.
Return: A Base64-encoded string suitable for use in a METADATA_BLOCK_PICTURE
tag.*/
char *parse_picture_specification(const char *filename, int picture_type, const char *description,
int *error, int *seen_file_icons){
FILE *picture_file;
opus_uint32 width;
opus_uint32 height;
opus_uint32 depth;
opus_uint32 colors;
unsigned char *buf;
const char *mime_type;
char *out;
size_t cbuf;
size_t nbuf;
size_t data_offset;
size_t data_length;
size_t b64_length;
*error = OPE_OK;
/*If a filename has a '|' in it, there's no way we can distinguish it from a
full specification just from the spec string.
Instead, try to open the file.
If it exists, the user probably meant the file.*/
if (picture_type < 0) picture_type=3;
if (description == NULL) description = "";
picture_file=fopen(filename,"rb");
/*Buffer size: 8 static 4-byte fields plus 2 dynamic fields, plus the
file/URL data.
We reserve at least 10 bytes for the media type, in case we still need to
extract it from the file.*/
data_offset=32+strlen(description)+10;
buf=NULL;
{
int has_palette;
/*Complicated case: we have a real file.
Read it in, attempt to parse the media type and image dimensions if
necessary, and validate what the user passed in.*/
if(picture_file==NULL){
*error = OPE_CANNOT_OPEN;
return NULL;
}
nbuf=data_offset;
/*Add a reasonable starting image file size.*/
cbuf=data_offset+65536;
for(;;){
unsigned char *new_buf;
size_t nread;
new_buf=realloc(buf,cbuf);
if(new_buf==NULL){
fclose(picture_file);
free(buf);
*error = OPE_ALLOC_FAIL;
return NULL;
}
buf=new_buf;
nread=fread(buf+nbuf,1,cbuf-nbuf,picture_file);
nbuf+=nread;
if(nbuf<cbuf){
int file_error;
file_error=ferror(picture_file);
fclose(picture_file);
if(file_error){
free(buf);
*error = OPE_INVALID_PICTURE;
return NULL;
}
break;
}
if(cbuf==0xFFFFFFFF){
fclose(picture_file);
free(buf);
*error = OPE_INVALID_PICTURE;
return NULL;
}
else if(cbuf>0x7FFFFFFFU)cbuf=0xFFFFFFFFU;
else cbuf=cbuf<<1|1;
}
data_length=nbuf-data_offset;
/*Try to extract the image dimensions/color information from the file.*/
width=height=depth=colors=0;
has_palette=-1;
{
if(is_jpeg(buf+data_offset,data_length)){
mime_type="image/jpeg";
extract_jpeg_params(buf+data_offset,data_length,
&width,&height,&depth,&colors,&has_palette);
}
else if(is_png(buf+data_offset,data_length)){
mime_type="image/png";
extract_png_params(buf+data_offset,data_length,
&width,&height,&depth,&colors,&has_palette);
}
else if(is_gif(buf+data_offset,data_length)){
mime_type="image/gif";
extract_gif_params(buf+data_offset,data_length,
&width,&height,&depth,&colors,&has_palette);
}
else{
free(buf);
*error = OPE_INVALID_PICTURE;
return NULL;
}
}
}
/*These fields MUST be set correctly OR all set to zero.
So if any of them (except colors, for which 0 is a valid value) are still
zero, clear the rest to zero.*/
if(width==0||height==0||depth==0)width=height=depth=colors=0;
if(picture_type==1&&(width!=32||height!=32
||strlen(mime_type)!=9
||oi_strncasecmp("image/png",mime_type,9)!=0)){
free(buf);
*error = OPE_INVALID_ICON;
return NULL;
}
/*Build the METADATA_BLOCK_PICTURE buffer.
We do this backwards from data_offset, because we didn't necessarily know
how big the media type string was before we read the data in.*/
data_offset-=4;
WRITE_U32_BE(buf+data_offset,(unsigned long)data_length);
data_offset-=4;
WRITE_U32_BE(buf+data_offset,colors);
data_offset-=4;
WRITE_U32_BE(buf+data_offset,depth);
data_offset-=4;
WRITE_U32_BE(buf+data_offset,height);
data_offset-=4;
WRITE_U32_BE(buf+data_offset,width);
data_offset-=strlen(description);
memcpy(buf+data_offset,description,strlen(description));
data_offset-=4;
WRITE_U32_BE(buf+data_offset,strlen(description));
data_offset-=strlen(mime_type);
memcpy(buf+data_offset,mime_type,strlen(mime_type));
data_offset-=4;
WRITE_U32_BE(buf+data_offset,strlen(mime_type));
data_offset-=4;
WRITE_U32_BE(buf+data_offset,picture_type);
data_length=nbuf-data_offset;
b64_length=BASE64_LENGTH(data_length);
out=(char *)malloc(b64_length+1);
if(out!=NULL){
base64_encode(out,(char *)buf+data_offset,data_length);
if(picture_type>=1&&picture_type<=2)*seen_file_icons|=picture_type;
} else {
*error = OPE_ALLOC_FAIL;
}
free(buf);
return out;
}