From 2fc85fe96e7e0e5fc433b98eacebf4d3511d2d58 Mon Sep 17 00:00:00 2001 From: Nidhi Makhijani Date: Sun, 6 Jul 2014 19:33:49 +0530 Subject: bmv: Split audio and video decoder Signed-off-by: Diego Biurrun --- libavcodec/bmvaudio.c | 91 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 libavcodec/bmvaudio.c (limited to 'libavcodec/bmvaudio.c') diff --git a/libavcodec/bmvaudio.c b/libavcodec/bmvaudio.c new file mode 100644 index 0000000..0f8c224 --- /dev/null +++ b/libavcodec/bmvaudio.c @@ -0,0 +1,91 @@ +/* + * Discworld II BMV audio decoder + * Copyright (c) 2011 Konstantin Shishkov + * + * 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 "libavutil/channel_layout.h" +#include "libavutil/common.h" + +#include "avcodec.h" +#include "internal.h" + +static const int bmv_aud_mults[16] = { + 16512, 8256, 4128, 2064, 1032, 516, 258, 192, 129, 88, 64, 56, 48, 40, 36, 32 +}; + +static av_cold int bmv_aud_decode_init(AVCodecContext *avctx) +{ + avctx->channels = 2; + avctx->channel_layout = AV_CH_LAYOUT_STEREO; + avctx->sample_fmt = AV_SAMPLE_FMT_S16; + + return 0; +} + +static int bmv_aud_decode_frame(AVCodecContext *avctx, void *data, + int *got_frame_ptr, AVPacket *avpkt) +{ + AVFrame *frame = data; + const uint8_t *buf = avpkt->data; + int buf_size = avpkt->size; + int blocks = 0, total_blocks, i; + int ret; + int16_t *output_samples; + int scale[2]; + + total_blocks = *buf++; + if (buf_size < total_blocks * 65 + 1) { + av_log(avctx, AV_LOG_ERROR, "expected %d bytes, got %d\n", + total_blocks * 65 + 1, buf_size); + return AVERROR_INVALIDDATA; + } + + /* get output buffer */ + frame->nb_samples = total_blocks * 32; + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) { + av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n"); + return ret; + } + output_samples = (int16_t *)frame->data[0]; + + for (blocks = 0; blocks < total_blocks; blocks++) { + uint8_t code = *buf++; + code = (code >> 1) | (code << 7); + scale[0] = bmv_aud_mults[code & 0xF]; + scale[1] = bmv_aud_mults[code >> 4]; + for (i = 0; i < 32; i++) { + *output_samples++ = av_clip_int16((scale[0] * (int8_t)*buf++) >> 5); + *output_samples++ = av_clip_int16((scale[1] * (int8_t)*buf++) >> 5); + } + } + + *got_frame_ptr = 1; + + return buf_size; +} + +AVCodec ff_bmv_audio_decoder = { + .name = "bmv_audio", + .long_name = NULL_IF_CONFIG_SMALL("Discworld II BMV audio"), + .type = AVMEDIA_TYPE_AUDIO, + .id = AV_CODEC_ID_BMV_AUDIO, + .init = bmv_aud_decode_init, + .decode = bmv_aud_decode_frame, + .capabilities = CODEC_CAP_DR1, +}; -- cgit v1.1