shithub: libopusenc

ref: 4099570a26f27bc11aa62cda2d6bd0898397f068
dir: /src/opusenc.c/

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/* Copyright (C)2002-2017 Jean-Marc Valin
   Copyright (C)2007-2013 Xiph.Org Foundation
   Copyright (C)2008-2013 Gregory Maxwell
   File: opusenc.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 COPYRIGHT OWNER
   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 <time.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <assert.h>
#include <opus_multistream.h>
#include "opusenc.h"
#include "opus_header.h"

#define LPC_PADDING 120

/* Allow up to 2 seconds for delayed decision. */
#define MAX_LOOKAHEAD 96000
/* We can't have a circular buffer (because of delayed decision), so let's not copy too often. */
#define BUFFER_EXTRA 24000

#define BUFFER_SAMPLES (MAX_LOOKAHEAD + BUFFER_EXTRA)

#define MIN(a,b) ((a) < (b) ? (a) : (b))
#define MAX(a,b) ((a) > (b) ? (a) : (b))

#define MAX_PACKET_SIZE (1276*8)

static int oe_write_page(ogg_page *page, OpusEncCallbacks *cb, void *user_data)
{
   int err;
   err = cb->write(user_data, page->header, page->header_len);
   if (err) return -1;
   err = cb->write(user_data, page->body, page->body_len);
   if (err) return -1;
   return page->header_len+page->body_len;
}

struct StdioObject {
  FILE *file;
};

struct OggOpusEnc {
  OpusMSEncoder *st;
  int channels;
  float *buffer;
  int buffer_start;
  int buffer_end;
  int frame_size;
  int decision_delay;
  ogg_int64_t curr_granule;
  ogg_int64_t end_granule;
  OpusEncCallbacks callbacks;
  void *user_data;
  OpusHeader header;
  char *comment;
  int comment_length;
  int os_allocated;
  ogg_stream_state os;
  int stream_is_init;
  int packetno;
};

static int oe_flush_page(OggOpusEnc *enc) {
  ogg_page og;
  int ret;
  int written = 0;
  while ( (ret = ogg_stream_flush(&enc->os, &og)) ) {
    if (!ret) break;
    ret = oe_write_page(&og, &enc->callbacks, enc->user_data);
    if (ret == -1) {
      return -1;
    }
    written += ret;
  }
  return written;
}

int stdio_write(void *user_data, const unsigned char *ptr, int len) {
  struct StdioObject *obj = (struct StdioObject*)user_data;
  return fwrite(ptr, 1, len, obj->file) != (size_t)len;
}

int stdio_close(void *user_data) {
  struct StdioObject *obj = (struct StdioObject*)user_data;
  int ret = fclose(obj->file);
  free(obj);
  return ret;
}

static const OpusEncCallbacks stdio_callbacks = {
  stdio_write,
  stdio_close
};

/* Create a new OggOpus file. */
OggOpusEnc *ope_create_file(const char *path, int rate, int channels, int family, int *error) {
  OggOpusEnc *enc;
  struct StdioObject *obj;
  obj = malloc(sizeof(*obj));
  enc = ope_create_callbacks(&stdio_callbacks, obj, rate, channels, family, error);
  if (enc == NULL || (error && *error)) {
    return NULL;
  }
  obj->file = fopen(path, "wb");
  if (!obj->file) {
    if (error) *error = OPE_CANNOT_OPEN;
    /* FIXME: Destroy the encoder properly. */
    free(obj);
    return NULL;
  }
  return enc;
}

/* Create a new OggOpus file (callback-based). */
OggOpusEnc *ope_create_callbacks(const OpusEncCallbacks *callbacks, void *user_data,
    int rate, int channels, int family, int *error) {
  OpusMSEncoder *st=NULL;
  OggOpusEnc *enc=NULL;
  int ret;
  if (family != 0 && family != 1 && family != 255) {
    if (error) *error = OPE_UNIMPLEMENTED;
    return NULL;
  }
  if (channels <= 0 || channels > 255) {
    if (error) *error = OPE_BAD_ARG;
    return NULL;
  }
  /* FIXME: Add resampling support. */
  if (rate != 48000) {
    if (error) *error = OPE_UNIMPLEMENTED;
    return NULL;
  }
  if ( (enc = malloc(sizeof(*enc))) == NULL) goto fail;
  enc->channels = channels;
  enc->frame_size = 960;
  enc->decision_delay = 96000;
  enc->header.channels=channels;
  enc->header.channel_mapping=family;
  enc->header.input_sample_rate=rate;
  enc->header.gain=0;
  st=opus_multistream_surround_encoder_create(48000, channels, enc->header.channel_mapping,
      &enc->header.nb_streams, &enc->header.nb_coupled,
      enc->header.stream_map, OPUS_APPLICATION_AUDIO, &ret);
  if (! (ret == OPUS_OK && st != NULL) ) {
    goto fail;
  }
  opus_multistream_encoder_ctl(st, OPUS_SET_EXPERT_FRAME_DURATION(OPUS_FRAMESIZE_20_MS));
  enc->os_allocated = 0;
  enc->stream_is_init = 0;
  enc->comment = NULL;
  {
    opus_int32 tmp;
    int ret;
    ret = opus_multistream_encoder_ctl(st, OPUS_GET_LOOKAHEAD(&tmp));
    if (ret == OPUS_OK) enc->curr_granule = -tmp;
    else enc->curr_granule = 0;
  }
  enc->end_granule = 0;
  comment_init(&enc->comment, &enc->comment_length, opus_get_version_string());
  {
    char encoder_string[1024];
    snprintf(encoder_string, sizeof(encoder_string), "%s version %s", PACKAGE_NAME, PACKAGE_VERSION);
    comment_add(&enc->comment, &enc->comment_length, "ENCODER", encoder_string);
  }
  if (enc->comment == NULL) goto fail;
  if ( (enc->buffer = malloc(sizeof(*enc->buffer)*BUFFER_SAMPLES*channels)) == NULL) goto fail;
  enc->buffer_start = enc->buffer_end = 0;
  enc->st = st;
  enc->callbacks = *callbacks;
  enc->user_data = user_data;
  if (error) *error = OPUS_OK;
  return enc;
fail:
  if (enc) {
    free(enc);
    if (enc->buffer) free(enc->buffer);
  }
  if (st) {
    opus_multistream_encoder_destroy(st);
  }
  return NULL;
}

static void init_stream(OggOpusEnc *enc) {
  time_t start_time;
  int serialno;
  assert(!enc->stream_is_init);
  start_time = time(NULL);
  srand(((getpid()&65535)<<15)^start_time);

  serialno = rand();
  if (ogg_stream_init(&enc->os, serialno) == -1) {
    assert(0);
    /* FIXME: How the hell do we handle that? */
  }
  /* FIXME: Compute preskip. */
  enc->header.preskip = 0;
  comment_pad(&enc->comment, &enc->comment_length, 512);

  /*Write header*/
  {
    ogg_packet op;
    /*The Identification Header is 19 bytes, plus a Channel Mapping Table for
      mapping families other than 0. The Channel Mapping Table is 2 bytes +
      1 byte per channel. Because the maximum number of channels is 255, the
      maximum size of this header is 19 + 2 + 255 = 276 bytes.*/
    unsigned char header_data[276];
    int packet_size = opus_header_to_packet(&enc->header, header_data, sizeof(header_data));
    op.packet=header_data;
    op.bytes=packet_size;
    op.b_o_s=1;
    op.e_o_s=0;
    op.granulepos=0;
    op.packetno=0;
    ogg_stream_packetin(&enc->os, &op);
    oe_flush_page(enc);

    op.packet = (unsigned char *)enc->comment;
    op.bytes = enc->comment_length;
    op.b_o_s = 0;
    op.e_o_s = 0;
    op.granulepos = 0;
    op.packetno = 1;
    ogg_stream_packetin(&enc->os, &op);
    oe_flush_page(enc);
  }
  enc->stream_is_init = 1;
  enc->packetno = 2;
}

static void shift_buffer(OggOpusEnc *enc) {
    memmove(enc->buffer, &enc->buffer[enc->channels*enc->buffer_start], enc->channels*(enc->buffer_end-enc->buffer_start)*sizeof(*enc->buffer));
    enc->buffer_end -= enc->buffer_start;
    enc->buffer_start = 0;
}

static void encode_buffer(OggOpusEnc *enc) {
  while (enc->buffer_end-enc->buffer_start > enc->frame_size + enc->decision_delay) {
    ogg_packet op;
    ogg_page og;
    int nbBytes;
    unsigned char packet[MAX_PACKET_SIZE];
    nbBytes = opus_multistream_encode_float(enc->st, &enc->buffer[enc->channels*enc->buffer_start],
        enc->buffer_end-enc->buffer_start, packet, MAX_PACKET_SIZE);
    /* FIXME: How do we handle failure here. */
    assert(nbBytes > 0);
    enc->curr_granule += enc->frame_size;
    op.packet=packet;
    op.bytes=nbBytes;
    op.b_o_s=0;
    op.e_o_s=0;
    op.packetno=enc->packetno++;
    op.granulepos=enc->curr_granule;
    if (enc->curr_granule >= enc->end_granule) {
      op.granulepos=enc->end_granule;
      ogg_stream_packetin(&enc->os, &op);
      while (ogg_stream_flush_fill(&enc->os, &og, 255*255)) {
        int ret = oe_write_page(&og, &enc->callbacks, enc->user_data);
        /* FIXME: what do we do if this fails? */
        assert(ret != -1);
        return;
      }
    }
    ogg_stream_packetin(&enc->os, &op);
    /* FIXME: Use flush to enforce latency constraint. */
    while (ogg_stream_pageout_fill(&enc->os, &og, 255*255)) {
      int ret = oe_write_page(&og, &enc->callbacks, enc->user_data);
      /* FIXME: what do we do if this fails? */
      assert(ret != -1);
    }
    enc->buffer_start += enc->frame_size;
  }
  /* If we've reached the end of the buffer, move everything back to the front. */
  if (enc->buffer_end == BUFFER_SAMPLES) {
    shift_buffer(enc);
  }
  /* This function must never leave the buffer full. */
  assert(enc->buffer_end < BUFFER_SAMPLES);
}

/* Add/encode any number of float samples to the file. */
int ope_write_float(OggOpusEnc *enc, const float *pcm, int samples_per_channel) {
  int channels = enc->channels;
  if (!enc->stream_is_init) init_stream(enc);
  enc->end_granule += samples_per_channel;
  /* FIXME: Add resampling support. */
  do {
    int i;
    int curr;
    int space_left = BUFFER_SAMPLES-enc->buffer_end;
    curr = MIN(samples_per_channel, space_left);
    for (i=0;i<channels*curr;i++) {
      enc->buffer[channels*enc->buffer_end+i] = pcm[i];
    }
    enc->buffer_end += curr;
    pcm += curr*channels;
    samples_per_channel -= curr;
    encode_buffer(enc);
  } while (samples_per_channel > 0);
  return OPE_OK;
}

/* Add/encode any number of int16 samples to the file. */
int ope_write(OggOpusEnc *enc, const opus_int16 *pcm, int samples_per_channel) {
  int channels = enc->channels;
  if (!enc->stream_is_init) init_stream(enc);
  enc->end_granule += samples_per_channel;
  /* FIXME: Add resampling support. */
  do {
    int i;
    int curr;
    int space_left = BUFFER_SAMPLES-enc->buffer_end;
    curr = MIN(samples_per_channel, space_left);
    for (i=0;i<channels*curr;i++) {
      enc->buffer[channels*enc->buffer_end+i] = (1.f/32768)*pcm[i];
    }
    enc->buffer_end += curr;
    pcm += curr*channels;
    samples_per_channel -= curr;
    encode_buffer(enc);
  } while (samples_per_channel > 0);
  return OPE_OK;
}

static void finalize_stream(OggOpusEnc *enc) {
  /* FIXME: Use a better value. */
  int pad_samples = 3000;
  if (!enc->stream_is_init) init_stream(enc);
  shift_buffer(enc);
  /* FIXME: Do LPC extension instead. */
  memset(&enc->buffer[enc->channels*enc->buffer_end], 0, pad_samples*enc->channels);
  enc->decision_delay = 0;
  enc->buffer_end += pad_samples;
  assert(enc->buffer_end <= BUFFER_SAMPLES);
  encode_buffer(enc);
}

/* Close/finalize the stream. */
int ope_close_and_free(OggOpusEnc *enc) {
  finalize_stream(enc);
  free(enc->buffer);
  opus_multistream_encoder_destroy(enc->st);
  if (enc->os_allocated) ogg_stream_clear(&enc->os);
  return OPE_OK;
}

/* Ends the stream and create a new stream within the same file. */
int ope_chain_current(OggOpusEnc *enc) {
  (void)enc;
  return OPE_UNIMPLEMENTED;
}

/* Ends the stream and create a new file. */
int ope_continue_new_file(OggOpusEnc *enc, const char *path) {
  (void)enc;
  (void)path;
  return OPE_UNIMPLEMENTED;
}

/* Ends the stream and create a new file (callback-based). */
int ope_continue_new_callbacks(OggOpusEnc *enc, void *user_data) {
  (void)enc;
  (void)user_data;
  return OPE_UNIMPLEMENTED;
}

/* Add a comment to the file (can only be called before encoding samples). */
int ope_add_comment(OggOpusEnc *enc, const char *tag, const char *val) {
  if (comment_add(&enc->comment, &enc->comment_length, tag, val)) return OPE_INTERNAL_ERROR;
  return OPE_OK;
}

/* Sets the Opus comment vendor string (optional, defaults to library info). */
int ope_set_vendor_string(OggOpusEnc *enc, const char *vendor) {
  (void)enc;
  (void)vendor;
  return OPE_UNIMPLEMENTED;
}

/* Goes straight to the libopus ctl() functions. */
int ope_encoder_ctl(OggOpusEnc *enc, int request, ...) {
  (void)enc;
  (void)request;
  return OPE_UNIMPLEMENTED;
}

/* ctl()-type call for the OggOpus layer. */
int ope_set_params(OggOpusEnc *enc, int request, ...) {
  (void)enc;
  (void)request;
  return OPE_UNIMPLEMENTED;
}