libgsm: Split decoder and encoder

Signed-off-by: Diego Biurrun <diego@biurrun.de>

1 files changed, 151 insertions, 0 deletions

diff --git a/libavcodec/libgsmdec.c b/libavcodec/libgsmdec.c
new file mode 100644
index 0000000000..da95cc7185
--- /dev/null
+++ b/libavcodec/libgsmdec.c
@@ -0,0 +1,151 @@
+/*
+ * Interface to libgsm for GSM decoding
+ * Copyright (c) 2005 Alban Bedel <albeu@free.fr>
+ * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Interface to libgsm for GSM decoding
+ */
+
+// The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html
+
+#include "config.h"
+#if HAVE_GSM_H
+#include <gsm.h>
+#else
+#include <gsm/gsm.h>
+#endif
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/common.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "gsm.h"
+
+typedef struct LibGSMDecodeContext {
+    struct gsm_state *state;
+} LibGSMDecodeContext;
+
+static av_cold int libgsm_decode_init(AVCodecContext *avctx) {
+    LibGSMDecodeContext *s = avctx->priv_data;
+
+    avctx->channels       = 1;
+    avctx->channel_layout = AV_CH_LAYOUT_MONO;
+    avctx->sample_rate    = 8000;
+    avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
+
+    s->state = gsm_create();
+
+    switch(avctx->codec_id) {
+    case AV_CODEC_ID_GSM:
+        avctx->frame_size  = GSM_FRAME_SIZE;
+        avctx->block_align = GSM_BLOCK_SIZE;
+        break;
+    case AV_CODEC_ID_GSM_MS: {
+        int one = 1;
+        gsm_option(s->state, GSM_OPT_WAV49, &one);
+        avctx->frame_size  = 2 * GSM_FRAME_SIZE;
+        avctx->block_align = GSM_MS_BLOCK_SIZE;
+        }
+    }
+
+    return 0;
+}
+
+static av_cold int libgsm_decode_close(AVCodecContext *avctx) {
+    LibGSMDecodeContext *s = avctx->priv_data;
+
+    gsm_destroy(s->state);
+    s->state = NULL;
+    return 0;
+}
+
+static int libgsm_decode_frame(AVCodecContext *avctx, void *data,
+                               int *got_frame_ptr, AVPacket *avpkt)
+{
+    int i, ret;
+    LibGSMDecodeContext *s = avctx->priv_data;
+    AVFrame *frame         = data;
+    uint8_t *buf = avpkt->data;
+    int buf_size = avpkt->size;
+    int16_t *samples;
+
+    if (buf_size < avctx->block_align) {
+        av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* get output buffer */
+    frame->nb_samples = avctx->frame_size;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
+        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
+        return ret;
+    }
+    samples = (int16_t *)frame->data[0];
+
+    for (i = 0; i < avctx->frame_size / GSM_FRAME_SIZE; i++) {
+        if ((ret = gsm_decode(s->state, buf, samples)) < 0)
+            return -1;
+        buf     += GSM_BLOCK_SIZE;
+        samples += GSM_FRAME_SIZE;
+    }
+
+    *got_frame_ptr = 1;
+
+    return avctx->block_align;
+}
+
+static void libgsm_flush(AVCodecContext *avctx) {
+    LibGSMDecodeContext *s = avctx->priv_data;
+    int one = 1;
+
+    gsm_destroy(s->state);
+    s->state = gsm_create();
+    if (avctx->codec_id == AV_CODEC_ID_GSM_MS)
+        gsm_option(s->state, GSM_OPT_WAV49, &one);
+}
+
+AVCodec ff_libgsm_decoder = {
+    .name           = "libgsm",
+    .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_GSM,
+    .priv_data_size = sizeof(LibGSMDecodeContext),
+    .init           = libgsm_decode_init,
+    .close          = libgsm_decode_close,
+    .decode         = libgsm_decode_frame,
+    .flush          = libgsm_flush,
+    .capabilities   = CODEC_CAP_DR1,
+};
+
+AVCodec ff_libgsm_ms_decoder = {
+    .name           = "libgsm_ms",
+    .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_GSM_MS,
+    .priv_data_size = sizeof(LibGSMDecodeContext),
+    .init           = libgsm_decode_init,
+    .close          = libgsm_decode_close,
+    .decode         = libgsm_decode_frame,
+    .flush          = libgsm_flush,
+    .capabilities   = CODEC_CAP_DR1,
+};