Speex decoding via libspeex

Originally committed as revision 15676 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 144 insertions, 0 deletions

diff --git a/libavcodec/libspeexdec.c b/libavcodec/libspeexdec.c
new file mode 100644
index 0000000000..7ea348901b
--- /dev/null
+++ b/libavcodec/libspeexdec.c
@@ -0,0 +1,144 @@
+/*
+ * Copyright (C) 2008 David Conrad
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg 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.
+ *
+ * FFmpeg 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 FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include "avcodec.h"
+#include <speex/speex.h>
+#include <speex/speex_header.h>
+#include <speex/speex_stereo.h>
+#include <speex/speex_callbacks.h>
+
+typedef struct {
+    SpeexBits bits;
+    SpeexStereoState stereo;
+    void *dec_state;
+    SpeexHeader *header;
+} LibSpeexContext;
+
+
+static av_cold int libspeex_decode_init(AVCodecContext *avctx)
+{
+    LibSpeexContext *s = avctx->priv_data;
+    const SpeexMode *mode;
+
+    // defaults in the case of a missing header
+    if (avctx->sample_rate <= 8000)
+        mode = &speex_nb_mode;
+    else if (avctx->sample_rate <= 16000)
+        mode = &speex_wb_mode;
+    else
+        mode = &speex_uwb_mode;
+
+    if (avctx->extradata_size >= 80)
+        s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
+
+    avctx->sample_fmt = SAMPLE_FMT_S16;
+    if (s->header) {
+        avctx->sample_rate = s->header->rate;
+        avctx->channels    = s->header->nb_channels;
+        avctx->frame_size  = s->header->frame_size;
+
+        mode = speex_lib_get_mode(s->header->mode);
+        if (!mode) {
+            av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
+            return -1;
+        }
+    } else
+        av_log(avctx, AV_LOG_INFO, "Missing speex header, assuming defaults\n");
+
+    if (avctx->channels > 2) {
+        av_log(avctx, AV_LOG_ERROR, "Only stereo and mono supported\n");
+        return -1;
+    }
+
+    speex_bits_init(&s->bits);
+    s->dec_state = speex_decoder_init(mode);
+    if (!s->dec_state) {
+        av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder\n");
+        return -1;
+    }
+
+    if (!s->header)
+        speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &avctx->frame_size);
+
+    if (avctx->channels == 2) {
+        SpeexCallback callback;
+        callback.callback_id = SPEEX_INBAND_STEREO;
+        callback.func = speex_std_stereo_request_handler;
+        callback.data = &s->stereo;
+        s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
+        speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
+    }
+    return 0;
+}
+
+static int libspeex_decode_frame(AVCodecContext *avctx,
+                                 void *data, int *data_size,
+                                 const uint8_t *buf, int buf_size)
+{
+    LibSpeexContext *s = avctx->priv_data;
+    int16_t *output = data, *end;
+    int i, num_samples;
+
+    num_samples = avctx->frame_size * avctx->channels;
+    end = output + *data_size/2;
+
+    speex_bits_read_from(&s->bits, buf, buf_size);
+
+    for (i = 0; speex_bits_remaining(&s->bits) && output + num_samples < end; i++) {
+        int ret = speex_decode_int(s->dec_state, &s->bits, output);
+        if (ret <= -2) {
+            av_log(avctx, AV_LOG_ERROR, "Error decoding speex frame\n");
+            return -1;
+        } else if (ret == -1)
+            // end of stream
+            break;
+
+        if (avctx->channels == 2)
+            speex_decode_stereo_int(output, avctx->frame_size, &s->stereo);
+
+        output += num_samples;
+    }
+
+    *data_size = i * avctx->channels * avctx->frame_size * 2;
+    return buf_size;
+}
+
+static av_cold int libspeex_decode_close(AVCodecContext *avctx)
+{
+    LibSpeexContext *s = avctx->priv_data;
+
+    speex_header_free(s->header);
+    speex_bits_destroy(&s->bits);
+    speex_decoder_destroy(s->dec_state);
+
+    return 0;
+}
+
+AVCodec libspeex_decoder = {
+    "libspeex",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_SPEEX,
+    sizeof(LibSpeexContext),
+    libspeex_decode_init,
+    NULL,
+    libspeex_decode_close,
+    libspeex_decode_frame,
+    .long_name = NULL_IF_CONFIG_SMALL("libspeex"),
+};