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tdemultimedia/mpg123_artsplugin/mpg123/readers.c

619 lines
13 KiB

#include <stdlib.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include "mpg123.h"
#include "buffer.h"
#include "common.h"
#ifdef READ_MMAP
#include <sys/mman.h>
#ifndef MAP_FAILED
#define MAP_FAILED ( (void *) -1 )
#endif
#endif
static int get_fileinfo(struct reader *,char *buf);
static void readers_add_data(struct reader *rds,unsigned char *buf,int len);
/* can hold 4096-1 = 4095 bytes! */
#define BACKBUF_SIZE (8192)
/*******************************************************************
* stream based operation
*/
static int bufdiff(struct reader *rds,int start, int end)
{
return (end >= start) ? end - start : rds->bufsize + end - start;
}
static int fullread(struct reader *rds,int fd,unsigned char *buf,int count)
{
int ret,cnt=0;
while(cnt < count) {
int toread = count-cnt;
int num = bufdiff(rds,rds->bufpos,rds->bufend);
/* if we have some data in the backbuffer .. use it first */
if(num > 0) {
int part1,part2;
if(toread > num)
toread = num;
part1 = rds->bufsize - rds->bufpos;
if(part1 > toread)
part1 = toread;
part2 = toread - part1;
memcpy(buf+cnt,&rds->backbuf[rds->bufpos],part1);
if(part2 > 0)
memcpy(buf+cnt+part1,&rds->backbuf[0],part2);
rds->bufpos += toread;
if(rds->bufpos >= rds->bufsize)
rds->bufpos -= rds->bufsize;
ret = toread;
if(!rds->mark)
rds->bufstart = rds->bufpos;
}
else {
ret = read(fd,buf+cnt,toread);
if(ret < 0)
return ret;
if(ret == 0)
break;
if(rds->mark) {
readers_add_data(rds,buf+cnt,ret);
rds->bufpos = rds->bufend;
}
}
cnt += ret;
}
if(0)
{
int i;
fprintf(stderr,"Fullread2 %d\n",cnt);
for(i=0;i<cnt;i++) {
fprintf(stderr,"%02x ",buf[i]);
if(i % 16 == 15)
fprintf(stderr,"\n");
}
}
return cnt;
}
static void readers_add_data(struct reader *rds,unsigned char *buf,int len)
{
int diff,part1,part2,store = len;
if(store >= rds->bufsize)
store = rds->bufsize - 1;
/* check whether the new bytes would overwrite the buffer front */
diff = bufdiff(rds,rds->bufstart,rds->bufend);
if(diff+store >= rds->bufsize) {
fprintf(stderr,"Warning: backbuffer overfull %d %d\n",diff+store,rds->bufsize);
/* +1 because end should never be the same as start if the is data in the buffer */
rds->bufstart += diff + store + 1 - rds->bufsize;
if(rds->bufstart >= rds->bufsize)
rds->bufstart -= rds->bufsize;
}
part1 = rds->bufsize - rds->bufend;
if(part1 > store)
part1 = store;
part2 = store - part1;
memcpy(rds->backbuf+rds->bufend,&buf[len-part1+part2],part1);
if(part2 > 0)
memcpy(rds->backbuf,&buf[len-part2],part2);
rds->bufend += store;
if(rds->bufend >= rds->bufsize)
rds->bufend -= rds->bufsize;
}
void readers_pushback_header(struct reader *rds,unsigned long aLong)
{
unsigned char buf[4];
if(rds->mark || (rds->bufpos != rds->bufend) ) {
rds->bufpos -= 4;
if(rds->bufpos < 0)
rds->bufpos += rds->bufsize;
}
else {
buf[0] = (aLong>>24) & 0xff;
buf[1] = (aLong>>16) & 0xff;
buf[2] = (aLong>>8) & 0xff;
buf[3] = (aLong>>0) & 0xff;
}
readers_add_data(rds,buf,4);
}
void readers_mark_pos(struct reader *rds) {
/* fprintf(stderr,"M%d ",rds->bufpos); */
rds->bufstart = rds->bufpos;
rds->mark = 1;
}
void readers_goto_mark(struct reader *rds) {
/* fprintf(stderr,"G%d ",rds->bufstart); */
rds->mark = 0;
rds->bufpos = rds->bufstart;
}
static int default_init(struct reader *rds)
{
char buf[128];
rds->mark = 0;
rds->bufend = 0;
rds->bufstart = 0;
rds->bufpos = 0;
rds->bufsize = BACKBUF_SIZE;
rds->backbuf = (unsigned char *) malloc(rds->bufsize);
rds->filepos = 0;
rds->filelen = get_fileinfo(rds,buf);
if(rds->filelen > 0) {
if(!strncmp(buf,"TAG",3)) {
rds->flags |= READER_ID3TAG;
memcpy(rds->id3buf,buf,128);
}
}
return 0;
}
void stream_close(struct reader *rds)
{
if (rds->flags & READER_FD_OPENED)
close(rds->filept);
}
/****************************************
* HACK,HACK,HACK: step back <num> frames
* can only work if the 'stream' isn't a real stream but a file
*/
static int stream_back_bytes(struct reader *rds,int bytes)
{
if(lseek(rds->filept,-bytes,SEEK_CUR) < 0)
return -1;
if(param.usebuffer)
buffer_resync();
return 0;
}
static int stream_back_frame(struct reader *rds,struct frame *fr,int num)
{
long bytes;
int skipped;
if(!fr->firsthead)
return 0;
bytes = (fr->framesize+8)*(num+2);
/* Skipping back/forth requires a bit more work in buffered mode.
* See mapped_back_frame().
*/
#ifndef NOXFERMEM
if(param.usebuffer)
bytes += (long)(xfermem_get_usedspace(buffermem) /
(buffermem->buf[0] * buffermem->buf[1]
* (buffermem->buf[2] & AUDIO_FORMAT_MASK ?
16.0 : 8.0 ))
* (tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index] << 10));
#endif
/*
bytes += (long)(compute_buffer_offset(fr)*compute_bpf(fr));
*/
if(lseek(rds->filept,-bytes,SEEK_CUR) < 0)
return -1;
sync_stream(rds,fr,0xffff,&skipped);
read_frame(rds,fr);
read_frame(rds,fr);
if(fr->lay == 3) {
set_pointer(fr->sideInfoSize,512);
}
if(param.usebuffer)
buffer_resync();
return 0;
}
static int stream_head_read(struct reader *rds,unsigned long *newhead)
{
unsigned char hbuf[4];
if(fullread(rds,rds->filept,hbuf,4) != 4)
return FALSE;
*newhead = ((unsigned long) hbuf[0] << 24) |
((unsigned long) hbuf[1] << 16) |
((unsigned long) hbuf[2] << 8) |
(unsigned long) hbuf[3];
return TRUE;
}
static int stream_head_shift(struct reader *rds,unsigned long *head)
{
unsigned char hbuf;
if(fullread(rds,rds->filept,&hbuf,1) != 1)
return 0;
*head <<= 8;
*head |= hbuf;
*head &= 0xffffffff;
return 1;
}
static int stream_skip_bytes(struct reader *rds,int len)
{
if (!param.usebuffer)
return lseek(rds->filept,len,SEEK_CUR);
else {
int ret = lseek(rds->filept,len,SEEK_CUR);
buffer_resync();
return ret;
}
}
static int stream_read_frame_body(struct reader *rds,unsigned char *buf,
int size)
{
long l;
if( (l=fullread(rds,rds->filept,buf,size)) != size)
{
if(l <= 0)
return 0;
memset(buf+l,0,size-l);
}
return 1;
}
static long stream_tell(struct reader *rds)
{
return lseek(rds->filept,0,SEEK_CUR);
}
static void stream_rewind(struct reader *rds)
{
lseek(rds->filept,0,SEEK_SET);
if(param.usebuffer)
buffer_resync();
}
/*
* returns length of a file (if filept points to a file)
* reads the last 128 bytes information into buffer
*/
static int get_fileinfo(struct reader *rds,char *buf)
{
int len;
if((len=lseek(rds->filept,0,SEEK_END)) < 0) {
return -1;
}
if(lseek(rds->filept,-128,SEEK_END) < 0)
return -1;
if(fullread(rds,rds->filept,(unsigned char *)buf,128) != 128) {
return -1;
}
if(!strncmp(buf,"TAG",3)) {
len -= 128;
}
if(lseek(rds->filept,0,SEEK_SET) < 0)
return -1;
if(len <= 0)
return -1;
return len;
}
#ifdef READ_MMAP
/*********************************************************+
* memory mapped operation
*
*/
static unsigned char *mapbuf;
static unsigned char *mappnt;
static unsigned char *mapend;
static int mapped_init(struct reader *rds)
{
long len;
char buf[128];
len = get_fileinfo(rds,buf);
if(len < 0)
return -1;
if(!strncmp(buf,"TAG",3)) {
rds->flags |= READER_ID3TAG;
memcpy(rds->id3buf,buf,128);
}
mappnt = mapbuf = (unsigned char *)
mmap(NULL, len, PROT_READ, MAP_SHARED , rds->filept, 0);
if(!mapbuf || mapbuf == MAP_FAILED)
return -1;
mapend = mapbuf + len;
if(param.verbose > 1)
fprintf(stderr,"Using memory mapped IO for this stream.\n");
rds->filelen = len;
return 0;
}
static void mapped_rewind(struct reader *rds)
{
mappnt = mapbuf;
if (param.usebuffer)
buffer_resync();
}
static void mapped_close(struct reader *rds)
{
munmap((void *)mapbuf,mapend-mapbuf);
if (rds->flags & READER_FD_OPENED)
close(rds->filept);
}
static int mapped_head_read(struct reader *rds,unsigned long *newhead)
{
unsigned long nh;
if(mappnt + 4 > mapend)
return FALSE;
nh = (*mappnt++) << 24;
nh |= (*mappnt++) << 16;
nh |= (*mappnt++) << 8;
nh |= (*mappnt++) ;
*newhead = nh;
return TRUE;
}
static int mapped_head_shift(struct reader *rds,unsigned long *head)
{
if(mappnt + 1 > mapend)
return FALSE;
*head <<= 8;
*head |= *mappnt++;
*head &= 0xffffffff;
return TRUE;
}
static int mapped_skip_bytes(struct reader *rds,int len)
{
if(mappnt + len > mapend)
return FALSE;
mappnt += len;
if (param.usebuffer)
buffer_resync();
return TRUE;
}
static int mapped_read_frame_body(struct reader *rds,unsigned char *buf,
int size)
{
if(size <= 0) {
fprintf(stderr,"Ouch. Read_frame called with size <= 0\n");
return FALSE;
}
if(mappnt + size > mapend)
return FALSE;
memcpy(buf,mappnt,size);
mappnt += size;
return TRUE;
}
static int mapped_back_bytes(struct reader *rds,int bytes)
{
if( (mappnt - bytes) < mapbuf || (mappnt - bytes + 4) > mapend)
return -1;
mappnt -= bytes;
if(param.usebuffer)
buffer_resync();
return 0;
}
static int mapped_back_frame(struct reader *rds,struct frame *fr,int num)
{
long bytes;
unsigned long newhead;
if(!firsthead)
return 0;
bytes = (fr->framesize+8)*(num+2);
/* Buffered mode is a bit trickier. From the size of the buffered
* output audio stream we have to make a guess at the number of frames
* this corresponds to.
*/
#ifndef NOXFERMEM
if(param.usebuffer)
bytes += (long)(xfermem_get_usedspace(buffermem) /
(buffermem->buf[0] * buffermem->buf[1]
* (buffermem->buf[2] & AUDIO_FORMAT_MASK ?
16.0 : 8.0 ))
* (tabsel_123[fr->lsf][fr->lay-1][fr->bitrate_index] << 10));
#endif
/*
bytes += (long)(compute_buffer_offset(fr)*compute_bpf(fr));
*/
if( (mappnt - bytes) < mapbuf || (mappnt - bytes + 4) > mapend)
return -1;
mappnt -= bytes;
newhead = (mappnt[0]<<24) + (mappnt[1]<<16) + (mappnt[2]<<8) + mappnt[3];
mappnt += 4;
while( (newhead & HDRCMPMASK) != (firsthead & HDRCMPMASK) ) {
if(mappnt + 1 > mapend)
return -1;
newhead <<= 8;
newhead |= *mappnt++;
newhead &= 0xffffffff;
}
mappnt -= 4;
read_frame(fr);
read_frame(fr);
if(fr->lay == 3)
set_pointer(fr->sideInfoSize,512);
if(param.usebuffer)
buffer_resync();
return 0;
}
static long mapped_tell(struct reader *rds)
{
return mappnt - mapbuf;
}
#endif
/*****************************************************************
* read frame helper
*/
struct reader *rd;
struct reader readers[] = {
#ifdef READ_SYSTEM
{ system_init,
NULL, /* filled in by system_init() */
NULL,
NULL,
NULL,
NULL,
NULL,
NULL,
NULL } ,
#endif
#ifdef READ_MMAP
{ mapped_init,
mapped_close,
mapped_head_read,
mapped_head_shift,
mapped_skip_bytes,
mapped_read_frame_body,
mapped_back_bytes,
mapped_back_frame,
mapped_tell,
mapped_rewind } ,
#endif
{ default_init,
stream_close,
stream_head_read,
stream_head_shift,
stream_skip_bytes,
stream_read_frame_body,
stream_back_bytes,
stream_back_frame,
stream_tell,
stream_rewind } ,
{ NULL, }
};
/* open the device to read the bit stream from it */
struct reader *open_stream(const char *bs_filenam,int fd)
{
int i;
int filept_opened = 1;
int filept;
if (!bs_filenam) {
if(fd < 0) {
filept = 0;
filept_opened = 0;
}
else
filept = fd;
}
else if (!strncasecmp(bs_filenam, "http://", 7))
filept = http_open(bs_filenam);
else if (!strncasecmp(bs_filenam, "ftp://", 6))
filept = http_open(bs_filenam);
#ifndef O_BINARY
#define O_BINARY (0)
#endif
else if ( (filept = open(bs_filenam, O_RDONLY|O_BINARY)) < 0) {
perror (bs_filenam);
return NULL;
}
rd = NULL;
for(i=0;;i++) {
readers[i].filelen = -1;
readers[i].filept = filept;
readers[i].flags = 0;
if(filept_opened)
readers[i].flags |= READER_FD_OPENED;
if(!readers[i].init) {
fprintf(stderr,"Fatal error!\n");
exit(1);
}
if(readers[i].init(readers+i) >= 0) {
rd = &readers[i];
break;
}
}
if(rd && rd->flags & READER_ID3TAG) {
print_id3_tag(rd->id3buf);
}
return rd;
}