libgsm: Split decoder and encoder

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

1 files changed, 137 insertions, 0 deletions

diff --git a/libavcodec/libgsmenc.c b/libavcodec/libgsmenc.c
new file mode 100644
index 0000000000..8f51321d46
--- /dev/null
+++ b/libavcodec/libgsmenc.c
@@ -0,0 +1,137 @@
+/*
+ * Interface to libgsm for GSM encoding
+ * 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 encoding
+ */
+
+// 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/common.h"
+
+#include "avcodec.h"
+#include "internal.h"
+#include "gsm.h"
+
+static av_cold int libgsm_encode_init(AVCodecContext *avctx) {
+    if (avctx->channels > 1) {
+        av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n",
+               avctx->channels);
+        return -1;
+    }
+
+    if (avctx->sample_rate != 8000) {
+        av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n",
+               avctx->sample_rate);
+        if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
+            return -1;
+    }
+    if (avctx->bit_rate != 13000 /* Official */ &&
+        avctx->bit_rate != 13200 /* Very common */ &&
+        avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) {
+        av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %dbps\n",
+               avctx->bit_rate);
+        if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
+            return -1;
+    }
+
+    avctx->priv_data = 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(avctx->priv_data, 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_encode_close(AVCodecContext *avctx) {
+    gsm_destroy(avctx->priv_data);
+    avctx->priv_data = NULL;
+    return 0;
+}
+
+static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
+                               const AVFrame *frame, int *got_packet_ptr)
+{
+    int ret;
+    gsm_signal *samples = (gsm_signal *)frame->data[0];
+    struct gsm_state *state = avctx->priv_data;
+
+    if ((ret = ff_alloc_packet(avpkt, avctx->block_align))) {
+        av_log(avctx, AV_LOG_ERROR, "Error getting output packet\n");
+        return ret;
+    }
+
+    switch(avctx->codec_id) {
+    case AV_CODEC_ID_GSM:
+        gsm_encode(state, samples, avpkt->data);
+        break;
+    case AV_CODEC_ID_GSM_MS:
+        gsm_encode(state, samples,                  avpkt->data);
+        gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32);
+    }
+
+    *got_packet_ptr = 1;
+    return 0;
+}
+
+
+AVCodec ff_libgsm_encoder = {
+    .name           = "libgsm",
+    .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_GSM,
+    .init           = libgsm_encode_init,
+    .encode2        = libgsm_encode_frame,
+    .close          = libgsm_encode_close,
+    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
+                                                     AV_SAMPLE_FMT_NONE },
+};
+
+AVCodec ff_libgsm_ms_encoder = {
+    .name           = "libgsm_ms",
+    .long_name      = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_GSM_MS,
+    .init           = libgsm_encode_init,
+    .encode2        = libgsm_encode_frame,
+    .close          = libgsm_encode_close,
+    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
+                                                     AV_SAMPLE_FMT_NONE },
+};