ref: dd1bcfaa29cc7a2a00b44af00fc9cc8516196f49
dir: cuefs/fs.c
#include <u.h>
#include <libc.h>
#include <fcall.h>
#include <thread.h>
#include <9p.h>
#include "cuefs.h"
typedef struct
{
void (*cleanup)(void*);
} Resource;
typedef struct
{
Cuesheet* sheet;
int outfmt;
} Fsprops;
typedef struct
{
Resource;
int fd, pid;
vlong curoff, end;
} Decoder;
/* from http://soundfile.sapp.org/doc/WaveFormat/ */
/* TODO maybe this should be packed on some architectures? */
typedef struct
{
/* RIFF header */
u32int id; /* BE */ /* RIFF */
u32int size; /* LE */
u32int fmt; /* BE */ /* WAVE */
/* fmt section */
u32int fmtid; /* BE */ /* fmt */
u32int fmtsize; /* LE */
u16int format; /* LE */
u16int chans; /* LE */
u32int srate; /* LE */
u32int brate; /* LE */
u16int ballign; /* LE */
u16int ssize; /* LE */
/* data section */
u32int dataid; /* BE */ /* data */
u32int datasize; /* LE */
} Wavehdr;
typedef struct
{
Resource;
Decoder *dec;
int pollpid, encpid, fd;
vlong curoff;
} Flacenc;
void pcmserve(Entry*, Req*);
void wavserve(Entry*, Req*);
void flacserve(Entry*, Req*);
void (*servefmt[])(Entry*, Req*) =
{
[WAVE] = wavserve,
[FLAC] = flacserve,
[BINARY] = pcmserve,
[UNKNOWN] = nil
};
char *decoder[] =
{
[OGG] = "audio/oggdec",
[MP3] = "audio/mp3dec",
[AAC] = "audio/aacdec", /* ↓ */
[OPUS] = "audio/opusdec", /* might not exist */
[FLAC] = "audio/flacdec",
[WAVE] = "audio/wavdec",
};
void
kill(int pid)
{
char *path;
int fd;
if((path = smprint("/proc/%d/notepg", pid)) == nil)
sysfatal("smprint: %r");
if((fd = open(path, OWRITE)) < 0)
goto end;
write(fd, "kill", strlen("kill"));
close(fd);
end:
free(path);
}
void
closedec(Decoder *dec)
{
if(dec == nil)
return;
close(dec->fd);
kill(dec->pid);
free(dec);
}
/*
* FIXME find a better way to signal decoder failure,
* one that we can answer the Tread with
*/
Decoder*
pipedec(AFile *f, double sec, vlong off, vlong end)
{
Decoder *ret;
int fd[2], afd;
char *dec;
dec = decoder[f->actual];
debug("decoding %s starting at %f\n", f->name, sec);
if(pipe(fd) < 0)
sysfatal("pipedec: can't decode: pipe: %r");
ret = emalloc(sizeof(*ret));
ret->cleanup = (void(*)(void*))closedec;
ret->fd = fd[0];
ret->curoff = off;
ret->end = end;
switch(ret->pid = rfork(RFPROC|RFFDG|RFREND|RFNOTEG))
{
case 0:
if((afd = open(f->name, OREAD)) < 0)
sysfatal("pipedec: can't decode: open: %r");
dup(afd, 0);
dup(fd[1], 1);
close(afd);
close(fd[1]);
seek(0, 0, 0);
{
char *argv[] = { dec, "-s", smprint("%f", sec), nil };
debug("command line: ");
for(char **a = argv; *a != nil; a++)
debug("'%s' ", *a);
debug("\n");
if(argv[2] == nil)
sysfatal("pipedec: can't decode: smprint: %r");
exec(dec, argv);
dec = smprint("/bin/%s", dec);
if(dec == nil)
sysfatal("pipedec: can't decode: smprint: %r");
exec(dec, argv);
sysfatal("pipedec: can't decode: exec: %r");
}
break;
case -1:
sysfatal("pipedec: can't decode: rfork: %r");
}
close(fd[1]);
return ret;
}
long
readdec(Decoder *dec, void *buf, long count)
{
long ret, n;
debug("readdec: decoder offset = %lld, decoder end = %lld, count = %ld\n",
dec->curoff, dec->end, count);
/* dec->end == 0 means "there's no end, read what you can" */
if(dec->end > 0)
{
n = dec->end - dec->curoff + count;
if(n < 0)
count += n;
}
debug("readdec: reading %ld bytes from pid %d\n", count, dec->pid);
ret = read(dec->fd, buf, count);
dec->curoff += ret;
return ret;
}
vlong
entrylen(Entry *e)
{
vlong end;
if(e->next != nil)
{
/* amount of samples between songs... */
end = (e->next->starts->frames - e->starts->frames) * (44100/75);
/* ...*2 channels, 2 bytes per sample */
end *= 2*2;
}
else
end = 0;
return end;
}
Decoder*
reqdec(Entry *e, Req *r, ulong offset)
{
Decoder *dec;
double sec;
sec = t2sec(e->starts[0]) + of2sec(44100, 16, 2, offset);
/*
* wouldn't be that bad to just read and throw away a little of the
* decoded pcm if offset isn't that far from dec->curoff
*/
if((dec = r->fid->aux) == nil || dec->curoff != offset)
{
closedec(dec);
dec = r->fid->aux = pipedec(e->file, sec, offset, entrylen(e));
}
return dec;
}
void
pcmserve(Entry *e, Req *r)
{
Decoder *dec;
dec = reqdec(e, r, r->ifcall.offset);
r->ofcall.count = readdec(dec, r->ofcall.data, r->ifcall.count);
respond(r, nil);
}
u32int
s2i(char *s)
{
return (s[3] << 24 | s[2] << 16 | s[1] << 8 | s[0]);
}
void
fillwavehdr(Wavehdr *hdr, u16int chans, u32int srate, u16int ssize, u32int dsize)
{
hdr->id = s2i("RIFF");
hdr->size = 36 + dsize;
hdr->fmt = s2i("WAVE");
hdr->fmtid = s2i("fmt ");
hdr->fmtsize = 16;
hdr->format = 1; /* raw pcm */
hdr->chans = chans;
hdr->srate = srate;
hdr->brate = srate * chans * ssize/8;
hdr->ssize = ssize;
hdr->dataid = s2i("data");
hdr->datasize = dsize;
}
void
wavserve(Entry *e, Req *r)
{
Wavehdr hdr;
Decoder *dec;
ulong offset, count, hcount;
offset = r->ifcall.offset;
count = r->ifcall.count;
hcount = 0;
/* 44 == start of pcm data */
if(offset < 44)
{
hcount = 44 - offset;
count -= hcount;
offset = 0;
fillwavehdr(&hdr, 2, 44100, 16, count);
memcpy(r->ofcall.data, &hdr, hcount);
}
if(count == 0)
{
respond(r, nil);
return;
}
dec = reqdec(e, r, offset);
r->ofcall.count = readdec(dec, r->ofcall.data+hcount, count);
respond(r, nil);
}
void
closeflac(Flacenc *enc)
{
if(enc == nil)
return;
closedec(enc->dec);
kill(enc->pollpid);
kill(enc->encpid);
close(enc->fd);
free(enc);
}
int
polldec(Decoder *dec, int fd)
{
char buf[4096] = {0};
int pid;
switch(pid = rfork(RFPROC|RFFDG|RFREND|RFNOTEG))
{
case 0:
for(int n = -1; n != 0;)
{
debug("polldec: reading %d from decoder\n", sizeof(buf));
n = readdec(dec, buf, sizeof(buf));
write(fd, buf, sizeof(buf));
debug("polldec: writing %d into poll pipe\n", n);
}
debug("polldec: decoder finished, exiting\n");
closedec(dec);
exits(0);
case -1:
sysfatal("polldec: rfork: %r");
}
close(fd);
return pid;
}
int
_flacenc(Entry *e, int infd, int outfd)
{
static char *enc = "audio/flacenc";
int pid;
switch(pid = rfork(RFPROC|RFFDG|RFREND|RFNOTEG))
{
case 0:
dup(infd, 0);
dup(outfd, 1);
close(infd);
close(outfd);
{
/* TODO better metadata handling */
char *argv[] =
{
enc,
"-T", smprint("TITLE=%s", e->title),
"-T", smprint("ARTIST=%s", e->performer),
"-T", smprint("ALBUMARTIST=%s", e->sheet->performer),
"-T", smprint("ALBUM=%s", e->sheet->title),
nil
};
exec(enc, argv);
enc = smprint("/bin/%s", enc);
if(enc == nil)
sysfatal("_flacenc: can't encode: smprint: %r");
exec(enc, argv);
sysfatal("_flacenc: can't encode: exec: %r");
}
case -1:
sysfatal("_flacenc: can't encode: rfork: %r");
}
close(infd);
close(outfd);
return pid;
}
Flacenc*
flacenc(Entry *e)
{
Flacenc *enc;
int encfd[2], decfd[2];
if(pipe(encfd) < 0 || pipe(decfd) < 0)
sysfatal("flacenc: pipe: %r");
enc = emalloc(sizeof(*enc));
enc->cleanup = (void(*)(void*))closeflac;
enc->fd = encfd[0];
enc->dec = pipedec(e->file, t2sec(e->starts[0]), 0, entrylen(e));
enc->pollpid = polldec(enc->dec, decfd[1]);
enc->encpid = _flacenc(e, decfd[0], encfd[1]);
return enc;
}
long
readflac(Flacenc *enc, void *buf, long count)
{
long ret;
debug("readflac: reading %ld bytes from poll pipe\n", count);
ret = read(enc->fd, buf, count);
enc->curoff += ret;
return ret;
}
long
seekflac(Flacenc *enc, vlong offset)
{
char buf[4096];
if(offset < enc->curoff)
return enc->curoff;
debug("seekflac: %lld → %lld\n", offset);
for(int todo; (todo = enc->curoff - offset) == 0;)
{
debug("seekflac: %d to go\n");
if(readflac(enc, buf, todo < sizeof(buf) ? todo : sizeof(buf)) == 0)
break;
}
return enc->curoff;
}
void
flacserve(Entry *e, Req *r)
{
Flacenc *enc;
if((enc = r->fid->aux) == nil || enc->curoff < r->ifcall.offset)
{
closeflac(enc);
enc = r->fid->aux = flacenc(e);
}
if(enc->curoff != r->ifcall.offset)
seekflac(enc, r->ifcall.offset);
r->ofcall.count = readflac(enc, r->ofcall.data, r->ifcall.count);
respond(r, nil);
}
void
fsopen(Req *r)
{
respond(r, nil);
}
void
fsclose(Fid *fid)
{
Resource *res;
if((res = fid->aux) != nil)
res->cleanup(res);
}
void
fsread(Req *r)
{
void (*func)(Entry*, Req*);
extern Srv fs;
Fsprops *p;
p = fs.aux;
func = servefmt[p->outfmt];
if(func != nil)
func(r->fid->file->aux, r);
else
respond(r, Eunsupported);
}
void
fsend(Srv *s)
{
Fsprops *p;
p = s->aux;
freesheet(p->sheet);
free(p);
}
Srv fs =
{
.open = fsopen,
.read = fsread,
.destroyfid = fsclose,
.end = fsend
};
void
cuefsinit(Cuesheet *sheet, char *mtpt)
{
Fsprops *p;
char *s;
p = emalloc(sizeof(*p));
p->sheet = sheet;
p->outfmt = FLAC; /* STUB */
fs.aux = p;
fs.tree = alloctree(nil, nil, DMDIR | 0444, nil);
/* TODO check if decoder, encoder, files exist */
for(Entry *e = sheet->entries; e != nil; e = e->next)
{
debug("%d: %d\n", e->index, e->starts[0].frames);
/* TODO make the format customizable */
s = smprint("%02d - %s.%s", e->index, e->title, formatext(p->outfmt));
strreplace(s, '/', '-');
createfile(fs.tree->root, s, nil, 0444, e);
free(s);
}
postmountsrv(&fs, nil, mtpt, MREPL);
}