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/* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* Chunks of this code have been borrowed and influenced
* by flac/decode.c and the flac XMMS plugin.
*
*/
#include <memory.h>
#include <ogg/ogg.h>
#include <caml/alloc.h>
#include <caml/callback.h>
#include <caml/custom.h>
#include <caml/fail.h>
#include <caml/memory.h>
#include <caml/mlvalues.h>
#include <caml/signals.h>
#include <caml/threads.h>
#include <ocaml-ogg.h>
#include "flac_stubs.h"
/* C.f. http://flac.sourceforge.net/ogg_mapping.html */
CAMLprim value ocaml_flac_decoder_check_ogg(value v) {
CAMLparam1(v);
ogg_packet *p = Packet_val(v);
unsigned char *h = p->packet;
if (p->bytes < 9 ||
/* FLAC */
h[0] != 0x7f || h[1] != 'F' || h[2] != 'L' || h[3] != 'A' || h[4] != 'C')
CAMLreturn(Val_false);
CAMLreturn(Val_true);
}
CAMLprim value ocaml_flac_decoder_packet_data(value v) {
CAMLparam1(v);
CAMLlocal1(ans);
ogg_packet *p = Packet_val(v);
ans = caml_alloc_string(p->bytes);
memcpy((char *)String_val(ans), p->packet, p->bytes);
CAMLreturn(ans);
}
/* Encoder */
CAMLprim value ocaml_flac_encoder_ogg_init(value _enc, value _serialno) {
CAMLparam2(_enc, _serialno);
intnat serialno = Nativeint_val(_serialno);
ocaml_flac_encoder *enc = Encoder_val(_enc);
caml_release_runtime_system();
FLAC__stream_encoder_set_ogg_serial_number(enc->encoder, serialno);
FLAC__stream_encoder_init_ogg_stream(enc->encoder, NULL, enc_write_callback,
NULL, NULL, NULL,
(void *)&enc->callbacks);
caml_acquire_runtime_system();
CAMLreturn(Val_unit);
}
/* Ogg skeleton interface */
/* Wrappers */
static void write32le(unsigned char *ptr, ogg_uint32_t v) {
ptr[0] = v & 0xff;
ptr[1] = (v >> 8) & 0xff;
ptr[2] = (v >> 16) & 0xff;
ptr[3] = (v >> 24) & 0xff;
}
static void write64le(unsigned char *ptr, ogg_int64_t v) {
ogg_uint32_t hi = v >> 32;
ptr[0] = v & 0xff;
ptr[1] = (v >> 8) & 0xff;
ptr[2] = (v >> 16) & 0xff;
ptr[3] = (v >> 24) & 0xff;
ptr[4] = hi & 0xff;
ptr[5] = (hi >> 8) & 0xff;
ptr[6] = (hi >> 16) & 0xff;
ptr[7] = (hi >> 24) & 0xff;
}
/* Values from http://xiph.org/ogg/doc/skeleton.html */
#define FISBONE_IDENTIFIER "fisbone\0"
#define FISBONE_MESSAGE_HEADER_OFFSET 44
#define FISBONE_SIZE 52
/* Code from theorautils.c in ffmpeg2theora */
CAMLprim value ocaml_flac_skeleton_fisbone(value serial, value samplerate,
value start, value content) {
CAMLparam4(serial, samplerate, start, content);
CAMLlocal1(packet);
ogg_packet op;
int len = FISBONE_SIZE + caml_string_length(content);
memset(&op, 0, sizeof(op));
op.packet = malloc(len);
if (op.packet == NULL)
caml_raise_out_of_memory();
memset(op.packet, 0, len);
/* it will be the fisbone packet for the vorbis audio */
memcpy(op.packet, FISBONE_IDENTIFIER, 8); /* identifier */
write32le(
op.packet + 8,
FISBONE_MESSAGE_HEADER_OFFSET); /* offset of the message header fields */
write32le(op.packet + 12,
Nativeint_val(serial)); /* serialno of the vorbis stream */
write32le(op.packet + 16, 2); /* number of header packet, 2 for now. */
/* granulerate, temporal resolution of the bitstream in Hz */
write64le(op.packet + 20,
(ogg_int64_t)Int64_val(samplerate)); /* granulerate numerator */
write64le(op.packet + 28, (ogg_int64_t)1); /* granulerate denominator */
write64le(op.packet + 36, (ogg_int64_t)Int64_val(start)); /* start granule */
write32le(op.packet + 44, 2); /* preroll, for flac its 2 ??? */
*(op.packet + 48) = 0; /* granule shift, always 0 for flac */
memcpy(op.packet + FISBONE_SIZE, String_val(content),
caml_string_length(content));
op.b_o_s = 0;
op.e_o_s = 0;
op.bytes = len;
packet = value_of_packet(&op);
free(op.packet);
CAMLreturn(packet);
}
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