Add support for AMR-WB encoding via libvo-amrwbenc

The wrapper code is based on the libamr wrapper removed in SVN rev 19365.

Signed-off-by: Martin Storsjö <martin@martin.st>

1 files changed, 127 insertions, 0 deletions

diff --git a/libavcodec/libvo-amrwbenc.c b/libavcodec/libvo-amrwbenc.c
new file mode 100644
index 0000000000..6f26d9b8af
--- /dev/null
+++ b/libavcodec/libvo-amrwbenc.c
@@ -0,0 +1,127 @@
+/*
+ * AMR Audio encoder stub
+ * Copyright (c) 2003 the ffmpeg project
+ *
+ * This file is part of Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+#include <vo-amrwbenc/enc_if.h>
+
+#include "avcodec.h"
+
+static const char wb_bitrate_unsupported[] =
+    "bitrate not supported: use one of 6.6k, 8.85k, 12.65k, 14.25k, 15.85k, "
+    "18.25k, 19.85k, 23.05k, or 23.85k\n";
+
+typedef struct AMRWB_bitrates {
+    int rate;
+    int mode;
+} AMRWB_bitrates;
+
+typedef struct AMRWBContext {
+    void  *state;
+    int    mode;
+    int    allow_dtx;
+} AMRWBContext;
+
+static int getWBBitrateMode(int bitrate)
+{
+    /* make the correspondance between bitrate and mode */
+    AMRWB_bitrates rates[] = { { 6600, 0},
+                               { 8850, 1},
+                               {12650, 2},
+                               {14250, 3},
+                               {15850, 4},
+                               {18250, 5},
+                               {19850, 6},
+                               {23050, 7},
+                               {23850, 8}, };
+    int i;
+
+    for (i = 0; i < 9; i++)
+        if (rates[i].rate == bitrate)
+            return rates[i].mode;
+    /* no bitrate matching, return an error */
+    return -1;
+}
+
+static av_cold int amr_wb_encode_init(AVCodecContext *avctx)
+{
+    AMRWBContext *s = avctx->priv_data;
+
+    if (avctx->sample_rate != 16000) {
+        av_log(avctx, AV_LOG_ERROR, "Only 16000Hz sample rate supported\n");
+        return -1;
+    }
+
+    if (avctx->channels != 1) {
+        av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
+        return -1;
+    }
+
+    if ((s->mode = getWBBitrateMode(avctx->bit_rate)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, wb_bitrate_unsupported);
+        return -1;
+    }
+
+    avctx->frame_size  = 320;
+    avctx->coded_frame = avcodec_alloc_frame();
+
+    s->state     = E_IF_init();
+    s->allow_dtx = 0;
+
+    return 0;
+}
+
+static int amr_wb_encode_close(AVCodecContext *avctx)
+{
+    AMRWBContext *s = avctx->priv_data;
+
+    E_IF_exit(s->state);
+    av_freep(&avctx->coded_frame);
+    return 0;
+}
+
+static int amr_wb_encode_frame(AVCodecContext *avctx,
+                               unsigned char *frame/*out*/,
+                               int buf_size, void *data/*in*/)
+{
+    AMRWBContext *s = avctx->priv_data;
+    int size;
+
+    if ((s->mode = getWBBitrateMode(avctx->bit_rate)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, wb_bitrate_unsupported);
+        return -1;
+    }
+    size = E_IF_encode(s->state, s->mode, data, frame, s->allow_dtx);
+    return size;
+}
+
+AVCodec ff_libvo_amrwbenc_encoder = {
+    "libvo_amrwbenc",
+    CODEC_TYPE_AUDIO,
+    CODEC_ID_AMR_WB,
+    sizeof(AMRWBContext),
+    amr_wb_encode_init,
+    amr_wb_encode_frame,
+    amr_wb_encode_close,
+    NULL,
+    .sample_fmts = (enum SampleFormat[]){SAMPLE_FMT_S16,SAMPLE_FMT_NONE},
+    .long_name = NULL_IF_CONFIG_SMALL("libvo-amrwbenc Adaptive Multi-Rate "
+                                      "(AMR) Wide-Band"),
+};
+