From b4edbe9a0eb48423fbf249b0ca7fb62838bdb7f5 Mon Sep 17 00:00:00 2001 From: Nidhi Makhijani Date: Tue, 8 Jul 2014 09:03:35 +0530 Subject: libgsm: Split decoder and encoder Signed-off-by: Diego Biurrun --- libavcodec/libgsmdec.c | 151 +++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 151 insertions(+) create mode 100644 libavcodec/libgsmdec.c (limited to 'libavcodec/libgsmdec.c') 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 + * Copyright (c) 2006, 2007 Michel Bardiaux + * + * 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 +#else +#include +#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, +}; -- cgit v1.2.3