lame_codec.c

来自「这个库实现了录象功能」· C语言 代码 · 共 685 行 · 第 1/2 页

/*******************************************************************************
 lame_codec.c

 libquicktime - A library for reading and writing quicktime/avi/mp4 files.
 http://libquicktime.sourceforge.net

 Copyright (C) 2002 Heroine Virtual Ltd.
 Copyright (C) 2002-2007 Members of the libquicktime project.

 This library is free software; you can redistribute it and/or modify it under
 the terms of the GNU Lesser General Public License as published by the Free
 Software Foundation; either version 2.1 of the License, or (at your option)
 any later version.

 This library 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 Lesser General Public License for more
 details.

 You should have received a copy of the GNU Lesser General Public License along
 with this library; if not, write to the Free Software Foundation, Inc., 51
 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*******************************************************************************/ 

#include "lqt_private.h"
#include <lame/lame.h>
#include <stdlib.h>
#include <string.h>
#include <lame_codec.h>

#define LOG_DOMAIN "lame"

/*
 *  We decode all headers to figure out, how many COMPLETE frames we have encoded.
 */

/* The following code was ported from gmerlin_avdecoder (http://gmerlin.sourceforge.net) */

/* MPEG Audio header parsing code */

static int mpeg_bitrates[5][16] = {
  /* MPEG-1 */
  { 0,  32000,  64000,  96000, 128000, 160000, 192000, 224000,    // I
       256000, 288000, 320000, 352000, 384000, 416000, 448000, 0},
  { 0,  32000,  48000,  56000,  64000,  80000,  96000, 112000,    // II
       128000, 160000, 192000, 224000, 256000, 320000, 384000, 0 },
  { 0,  32000,  40000,  48000,  56000,  64000,  80000,  96000,    // III
       112000, 128000, 160000, 192000, 224000, 256000, 320000, 0 },

  /* MPEG-2 LSF */
  { 0,  32000,  48000,  56000,  64000,  80000,  96000, 112000,    // I
       128000, 144000, 160000, 176000, 192000, 224000, 256000, 0 },
  { 0,   8000,  16000,  24000,  32000,  40000,  48000,  56000,
        64000,  80000,  96000, 112000, 128000, 144000, 160000, 0 } // II & III
};

static int mpeg_samplerates[3][3] = {
  { 44100, 48000, 32000 }, // MPEG1
  { 22050, 24000, 16000 }, // MPEG2
  { 11025, 12000, 8000 }   // MPEG2.5
  };

#define MPEG_ID_MASK        0x00180000
#define MPEG_MPEG1          0x00180000
#define MPEG_MPEG2          0x00100000
#define MPEG_MPEG2_5        0x00000000

#define MPEG_LAYER_MASK     0x00060000
#define MPEG_LAYER_III      0x00020000
#define MPEG_LAYER_II       0x00040000
#define MPEG_LAYER_I        0x00060000
#define MPEG_PROTECTION     0x00010000
#define MPEG_BITRATE_MASK   0x0000F000
#define MPEG_FREQUENCY_MASK 0x00000C00
#define MPEG_PAD_MASK       0x00000200
#define MPEG_PRIVATE_MASK   0x00000100
#define MPEG_MODE_MASK      0x000000C0
#define MPEG_MODE_EXT_MASK  0x00000030
#define MPEG_COPYRIGHT_MASK 0x00000008
#define MPEG_HOME_MASK      0x00000004
#define MPEG_EMPHASIS_MASK  0x00000003
#define LAYER_I_SAMPLES       384
#define LAYER_II_III_SAMPLES 1152

/* Header detection stolen from the mpg123 plugin of xmms */

static int header_check(uint32_t head)
{
        if ((head & 0xffe00000) != 0xffe00000)
                return 0;
        if (!((head >> 17) & 3))
                return 0;
        if (((head >> 12) & 0xf) == 0xf)
                return 0;
        if (!((head >> 12) & 0xf))
                return 0;
        if (((head >> 10) & 0x3) == 0x3)
                return 0;
        if (((head >> 19) & 1) == 1 &&
            ((head >> 17) & 3) == 3 &&
            ((head >> 16) & 1) == 1)
                return 0;
        if ((head & 0xffff0000) == 0xfffe0000)
                return 0;
        return 1;
}

typedef enum
  {
    MPEG_VERSION_NONE = 0,
    MPEG_VERSION_1 = 1,
    MPEG_VERSION_2 = 2,
    MPEG_VERSION_2_5
  } mpeg_version_t;

#define CHANNEL_STEREO   0
#define CHANNEL_JSTEREO  1
#define CHANNEL_DUAL     2
#define CHANNEL_MONO     3

typedef struct
  {
  mpeg_version_t version;
  int layer;

  int bitrate_mode;
  int bitrate;
  
  int min_bitrate; /* ABR only */
  int max_bitrate; /* ABR only  */
  int samplerate;
  int frame_bytes;
  int channel_mode;
  int mode;
  int samples_per_frame;
  } mpeg_header;

static int decode_header(mpeg_header * h, uint8_t * ptr)
  {
  uint32_t header;
  int index;
  /* For calculation of the byte length of a frame */
  int pad;
  int slots_per_frame;
  h->frame_bytes = 0;
  header =
    ptr[3] | (ptr[2] << 8) | (ptr[1] << 16) | (ptr[0] << 24);
  if(!header_check(header))
    return 0;
  index = (header & MPEG_MODE_MASK) >> 6;
  switch(index)
    {
    case 0:
      h->channel_mode = CHANNEL_STEREO;
      break;
    case 1:
      h->channel_mode = CHANNEL_JSTEREO;
      break;
    case 2:
      h->channel_mode = CHANNEL_DUAL;
      break;
    case 3:
      h->channel_mode = CHANNEL_MONO;
      break;
    }
  /* Get Version */
  switch(header & MPEG_ID_MASK)
    {
    case MPEG_MPEG1:
      h->version = MPEG_VERSION_1;
        break;
    case MPEG_MPEG2:
      h->version = MPEG_VERSION_2;
      break;
    case MPEG_MPEG2_5:
      h->version = MPEG_VERSION_2_5;
      break;
    default:
      return 0;
    }
  /* Get Layer */
  switch(header & MPEG_LAYER_MASK)
    {
    case MPEG_LAYER_I:
      h->layer = 1;
      break;
    case MPEG_LAYER_II:
      h->layer = 2;
      break;
    case MPEG_LAYER_III:
      h->layer = 3;
      break;
    }
  index = (header & MPEG_BITRATE_MASK) >> 12;
  switch(h->version)
    {
    case MPEG_VERSION_1:
      switch(h->layer)
        {
        case 1:
          h->bitrate = mpeg_bitrates[0][index];
          break;
        case 2:
          h->bitrate = mpeg_bitrates[1][index];
          break;
        case 3:
          h->bitrate = mpeg_bitrates[2][index];
          break;
        }
      break;
    case MPEG_VERSION_2:
    case MPEG_VERSION_2_5:
      switch(h->layer)
        {
        case 1:
          h->bitrate = mpeg_bitrates[3][index];
          break;
        case 2:
        case 3:
          h->bitrate = mpeg_bitrates[4][index];
          break;
        }
      break;
    default: // This won't happen, but keeps gcc quiet
      return 0;
    }
  index = (header & MPEG_FREQUENCY_MASK) >> 10;
  switch(h->version)
    {
    case MPEG_VERSION_1:
      h->samplerate = mpeg_samplerates[0][index];
      break;
    case MPEG_VERSION_2:
      h->samplerate = mpeg_samplerates[1][index];
      break;
    case MPEG_VERSION_2_5:
      h->samplerate = mpeg_samplerates[2][index];
      break;
    default: // This won't happen, but keeps gcc quiet
      return 0;
    }
  pad = (header & MPEG_PAD_MASK) ? 1 : 0;
  if(h->layer == 1)
    {
    h->frame_bytes = ((12 * h->bitrate / h->samplerate) + pad) * 4;
    }
  else
    {
    slots_per_frame = ((h->layer == 3) &&
      ((h->version == MPEG_VERSION_2) ||
       (h->version == MPEG_VERSION_2_5))) ? 72 : 144;
    h->frame_bytes = (slots_per_frame * h->bitrate) / h->samplerate + pad;
    }
  // h->mode = (ptr[3] >> 6) & 3;
  h->samples_per_frame =
    (h->layer == 1) ? LAYER_I_SAMPLES : LAYER_II_III_SAMPLES;
  if(h->version != MPEG_VERSION_1)
    h->samples_per_frame /= 2;
  //  dump_header(h);
  return 1;
  }



typedef struct
  {
  // mp3 encoder
  lame_global_flags *lame_global;
  //        mpeg3_layer_t *encoded_header;
  int encode_initialized;
  int input_size;
  int input_allocated;
  
  unsigned char *encoder_output;
  int encoder_output_alloc;
  int encoder_output_size;
  
  int samples_per_frame;
  int stereo;

  int16_t * input_buffer[2];
  int input_buffer_alloc;

  int64_t samples_read;    /* samples passed to lame_encode_buffer */
  int64_t samples_written; /* samples written to the file          */

  /* Configuration stuff */
  int bitrate_mode;
  int bitrate;
  int bitrate_min;
  int bitrate_max;
  int quality;
  int quality_vbr;
  
  } quicktime_mp3_codec_t;

static int delete_codec(quicktime_audio_map_t *atrack)
  {
  quicktime_mp3_codec_t *codec = ((quicktime_codec_t*)atrack->codec)->priv;
  //  if(codec->mp3) mpeg3_delete_layer(codec->mp3);
  //  if(codec->mp3_header)  mpeg3_delete_layer(codec->mp3_header);
  //  if(codec->packet_buffer) free(codec->packet_buffer);
  /*   if(codec->output) */
  /*     { */
  /*     int i; */
  /*     for(i = 0; i < atrack->channels; i++) */
  /*       free(codec->output[i]); */
  /*     free(codec->output); */
  /*     } */

  
  if(codec->lame_global)
    {
    lame_close(codec->lame_global);
    }
  if(codec->input_buffer[0])
    free(codec->input_buffer[0]);
  if(codec->input_buffer[1])
    free(codec->input_buffer[1]);
  
  
  if(codec->encoder_output)
    free(codec->encoder_output);
  //  if(codec->encoded_header)  mpeg3_delete_layer(codec->encoded_header);
  free(codec);
  return 0;
  }


static int write_data(quicktime_t *file, int track,
                      quicktime_mp3_codec_t *codec, int samples)
  {
  mpeg_header h;
  quicktime_atom_t chunk_atom;
  int result = 0;
  int chunk_bytes = 0, chunk_samples = 0;
  quicktime_audio_map_t *track_map;
  uint8_t * chunk_ptr;

  track_map = &file->atracks[track];
  
  memset(&h, 0, sizeof(h));