libavcodec/libspeexdec.c

   1 /*
   2  * Copyright (C) 2008 David Conrad
   3  *
   4  * This file is part of Libav.
   5  *
   6  * Libav is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * Libav is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with Libav; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <speex/speex.h>
  22 #include <speex/speex_header.h>
  23 #include <speex/speex_stereo.h>
  24 #include <speex/speex_callbacks.h>
  25
  26 #include "libavutil/channel_layout.h"
  27 #include "libavutil/common.h"
  28 #include "avcodec.h"
  29 #include "internal.h"
  30
  31 typedef struct {
  32     SpeexBits bits;
  33     SpeexStereoState stereo;
  34     void *dec_state;
  35     int frame_size;
  36 } LibSpeexContext;
  37
  38
  39 static av_cold int libspeex_decode_init(AVCodecContext *avctx)
  40 {
  41     LibSpeexContext *s = avctx->priv_data;
  42     const SpeexMode *mode;
  43     SpeexHeader *header = NULL;
  44     int spx_mode;
  45
  46     avctx->sample_fmt = AV_SAMPLE_FMT_S16;
  47     if (avctx->extradata && avctx->extradata_size >= 80) {
  48         header = speex_packet_to_header(avctx->extradata,
  49                                         avctx->extradata_size);
  50         if (!header)
  51             av_log(avctx, AV_LOG_WARNING, "Invalid Speex header\n");
  52     }
  53     if (header) {
  54         avctx->channels    = header->nb_channels;
  55         spx_mode           = header->mode;
  56         speex_header_free(header);
  57     } else {
  58         switch (avctx->sample_rate) {
  59         case 8000:  spx_mode = 0; break;
  60         case 16000: spx_mode = 1; break;
  61         case 32000: spx_mode = 2; break;
  62         default:
  63             /* libspeex can handle any mode if initialized as ultra-wideband */
  64             av_log(avctx, AV_LOG_WARNING, "Invalid sample rate: %d\n"
  65                                           "Decoding as 32kHz ultra-wideband\n",
  66                                           avctx->sample_rate);
  67             spx_mode = 2;
  68         }
  69     }
  70
  71     mode = speex_lib_get_mode(spx_mode);
  72     if (!mode) {
  73         av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", spx_mode);
  74         return AVERROR_INVALIDDATA;
  75     }
  76     avctx->sample_rate = 8000 << spx_mode;
  77     s->frame_size      =  160 << spx_mode;
  78
  79     if (avctx->channels < 1 || avctx->channels > 2) {
  80         /* libspeex can handle mono or stereo if initialized as stereo */
  81         av_log(avctx, AV_LOG_ERROR, "Invalid channel count: %d.\n"
  82                                     "Decoding as stereo.\n", avctx->channels);
  83         avctx->channels = 2;
  84     }
  85     avctx->channel_layout = avctx->channels == 2 ? AV_CH_LAYOUT_STEREO :
  86                                                    AV_CH_LAYOUT_MONO;
  87
  88     speex_bits_init(&s->bits);
  89     s->dec_state = speex_decoder_init(mode);
  90     if (!s->dec_state) {
  91         av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder.\n");
  92         return -1;
  93     }
  94
  95     if (avctx->channels == 2) {
  96         SpeexCallback callback;
  97         callback.callback_id = SPEEX_INBAND_STEREO;
  98         callback.func = speex_std_stereo_request_handler;
  99         callback.data = &s->stereo;
 100         s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
 101         speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
 102     }
 103
 104     return 0;
 105 }
 106
 107 static int libspeex_decode_frame(AVCodecContext *avctx, void *data,
 108                                  int *got_frame_ptr, AVPacket *avpkt)
 109 {
 110     uint8_t *buf = avpkt->data;
 111     int buf_size = avpkt->size;
 112     LibSpeexContext *s = avctx->priv_data;
 113     AVFrame *frame     = data;
 114     int16_t *output;
 115     int ret, consumed = 0;
 116
 117     /* get output buffer */
 118     frame->nb_samples = s->frame_size;
 119     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
 120         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 121         return ret;
 122     }
 123     output = (int16_t *)frame->data[0];
 124
 125     /* if there is not enough data left for the smallest possible frame or the
 126        next 5 bits are a terminator code, reset the libspeex buffer using the
 127        current packet, otherwise ignore the current packet and keep decoding
 128        frames from the libspeex buffer. */
 129     if (speex_bits_remaining(&s->bits) < 5 ||
 130         speex_bits_peek_unsigned(&s->bits, 5) == 0x1F) {
 131         /* check for flush packet */
 132         if (!buf || !buf_size) {
 133             *got_frame_ptr = 0;
 134             return buf_size;
 135         }
 136         /* set new buffer */
 137         speex_bits_read_from(&s->bits, buf, buf_size);
 138         consumed = buf_size;
 139     }
 140
 141     /* decode a single frame */
 142     ret = speex_decode_int(s->dec_state, &s->bits, output);
 143     if (ret <= -2) {
 144         av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
 145         return AVERROR_INVALIDDATA;
 146     }
 147     if (avctx->channels == 2)
 148         speex_decode_stereo_int(output, s->frame_size, &s->stereo);
 149
 150     *got_frame_ptr = 1;
 151
 152     return consumed;
 153 }
 154
 155 static av_cold int libspeex_decode_close(AVCodecContext *avctx)
 156 {
 157     LibSpeexContext *s = avctx->priv_data;
 158
 159     speex_bits_destroy(&s->bits);
 160     speex_decoder_destroy(s->dec_state);
 161
 162     return 0;
 163 }
 164
 165 static av_cold void libspeex_decode_flush(AVCodecContext *avctx)
 166 {
 167     LibSpeexContext *s = avctx->priv_data;
 168     speex_bits_reset(&s->bits);
 169 }
 170
 171 AVCodec ff_libspeex_decoder = {
 172     .name           = "libspeex",
 173     .type           = AVMEDIA_TYPE_AUDIO,
 174     .id             = AV_CODEC_ID_SPEEX,
 175     .priv_data_size = sizeof(LibSpeexContext),
 176     .init           = libspeex_decode_init,
 177     .close          = libspeex_decode_close,
 178     .decode         = libspeex_decode_frame,
 179     .flush          = libspeex_decode_flush,
 180     .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1,
 181     .long_name      = NULL_IF_CONFIG_SMALL("libspeex Speex"),
 182 };