libmpcodecs/ad_speex.c

   1 /**
   2  * Speex decoder by Reimar Döffinger <Reimar.Doeffinger@stud.uni-karlsruhe.de>
   3  * License: GPL v2 or later
   4  * This code may be be relicensed under the terms of the GNU LGPL when it
   5  * becomes part of the FFmpeg project (ffmpeg.org)
   6  */
   7 #include "config.h"
   8 #include <stdlib.h>
   9 #include <speex/speex.h>
  10 #include <speex/speex_stereo.h>
  11 #include <speex/speex_header.h>
  12 #include "ad_internal.h"
  13
  14 static const ad_info_t info ={
  15   "Speex audio decoder",
  16   "speex",
  17   "Reimar Döffinger",
  18   "",
  19   ""
  20 };
  21
  22 LIBAD_EXTERN(speex)
  23
  24 typedef struct {
  25   SpeexBits bits;
  26   void *dec_context;
  27   SpeexStereoState stereo;
  28   SpeexHeader *hdr;
  29 } context_t;
  30
  31 #define MAX_FRAMES_PER_PACKET 100
  32
  33 static int preinit(sh_audio_t *sh) {
  34   sh->audio_out_minsize = 2 * 320 * MAX_FRAMES_PER_PACKET * 2 * sizeof(short);
  35   return 1;
  36 }
  37
  38 static int init(sh_audio_t *sh) {
  39   context_t *ctx = calloc(1, sizeof(context_t));
  40   const SpeexMode *spx_mode;
  41   const SpeexStereoState st_st = SPEEX_STEREO_STATE_INIT; // hack
  42   if (!sh->wf || sh->wf->cbSize < 80) {
  43     mp_msg(MSGT_DECAUDIO, MSGL_FATAL, "Missing extradata!\n");
  44     return 0;
  45   }
  46   ctx->hdr = speex_packet_to_header((char *)&sh->wf[1], sh->wf->cbSize);
  47   if (ctx->hdr->nb_channels != 1 && ctx->hdr->nb_channels != 2) {
  48     mp_msg(MSGT_DECAUDIO, MSGL_WARN, "Invalid number of channels (%i), "
  49             "assuming mono\n", ctx->hdr->nb_channels);
  50     ctx->hdr->nb_channels = 1;
  51   }
  52   if (ctx->hdr->frames_per_packet > MAX_FRAMES_PER_PACKET) {
  53     mp_msg(MSGT_DECAUDIO, MSGL_WARN, "Invalid number of frames per packet (%i), "
  54             "assuming 1\n", ctx->hdr->frames_per_packet);
  55     ctx->hdr->frames_per_packet = 1;
  56   }
  57   switch (ctx->hdr->mode) {
  58     case 0:
  59       spx_mode = &speex_nb_mode; break;
  60     case 1:
  61       spx_mode = &speex_wb_mode; break;
  62     case 2:
  63       spx_mode = &speex_uwb_mode; break;
  64     default:
  65       mp_msg(MSGT_DECAUDIO, MSGL_WARN, "Unknown speex mode (%i)\n", ctx->hdr->mode);
  66       spx_mode = &speex_nb_mode;
  67   }
  68   ctx->dec_context = speex_decoder_init(spx_mode);
  69   speex_bits_init(&ctx->bits);
  70   memcpy(&ctx->stereo, &st_st, sizeof(ctx->stereo)); // hack part 2
  71   sh->channels = ctx->hdr->nb_channels;
  72   sh->samplerate = ctx->hdr->rate;
  73   sh->samplesize = 2;
  74   sh->sample_format = AF_FORMAT_S16_NE;
  75   sh->context = ctx;
  76   return 1;
  77 }
  78
  79 static void uninit(sh_audio_t *sh) {
  80   context_t *ctx = sh->context;
  81   if (ctx) {
  82     speex_bits_destroy(&ctx->bits);
  83     speex_decoder_destroy(ctx->dec_context);
  84     if (ctx->hdr)
  85       free(ctx->hdr);
  86     free(ctx);
  87   }
  88   ctx = NULL;
  89 }
  90
  91 static int decode_audio(sh_audio_t *sh, unsigned char *buf,
  92                         int minlen, int maxlen) {
  93   context_t *ctx = sh->context;
  94   int len, framelen, framesamples;
  95   char *packet;
  96   int i, err;
  97   speex_decoder_ctl(ctx->dec_context, SPEEX_GET_FRAME_SIZE, &framesamples);
  98   framelen = framesamples * ctx->hdr->nb_channels * sizeof(short);
  99   if (maxlen < ctx->hdr->frames_per_packet * framelen) {
 100     mp_msg(MSGT_DECAUDIO, MSGL_V, "maxlen too small in decode_audio\n");
 101     return -1;
 102   }
 103   len = ds_get_packet(sh->ds, (unsigned char **)&packet);
 104   if (len <= 0) return -1;
 105   speex_bits_read_from(&ctx->bits, packet, len);
 106   i = ctx->hdr->frames_per_packet;
 107   do {
 108     err = speex_decode_int(ctx->dec_context, &ctx->bits, (short *)buf);
 109     if (err == -2)
 110       mp_msg(MSGT_DECAUDIO, MSGL_ERR, "Error decoding file.\n");
 111     if (ctx->hdr->nb_channels == 2)
 112       speex_decode_stereo_int((short *)buf, framesamples, &ctx->stereo);
 113     buf = &buf[framelen];
 114   } while (--i > 0);
 115   return ctx->hdr->frames_per_packet * framelen;
 116 }
 117
 118 static int control(sh_audio_t *sh, int cmd, void *arg, ...) {
 119   return CONTROL_UNKNOWN;
 120 }
 121