mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-23 12:43:46 +02:00
4243da4ff4
This is possible, because every given FFCodec has to implement exactly one of these. Doing so decreases sizeof(FFCodec) and therefore decreases the size of the binary. Notice that in case of position-independent code the decrease is in .data.rel.ro, so that this translates to decreased memory consumption. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
91 lines
2.9 KiB
C
91 lines
2.9 KiB
C
/*
|
|
* Discworld II BMV audio decoder
|
|
* Copyright (c) 2011 Konstantin Shishkov
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg 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.
|
|
*
|
|
* FFmpeg 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 FFmpeg; 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 "codec_internal.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)
|
|
{
|
|
av_channel_layout_uninit(&avctx->ch_layout);
|
|
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO;
|
|
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static int bmv_aud_decode_frame(AVCodecContext *avctx, AVFrame *frame,
|
|
int *got_frame_ptr, AVPacket *avpkt)
|
|
{
|
|
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)
|
|
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;
|
|
}
|
|
|
|
const FFCodec ff_bmv_audio_decoder = {
|
|
.p.name = "bmv_audio",
|
|
.p.long_name = NULL_IF_CONFIG_SMALL("Discworld II BMV audio"),
|
|
.p.type = AVMEDIA_TYPE_AUDIO,
|
|
.p.id = AV_CODEC_ID_BMV_AUDIO,
|
|
.init = bmv_aud_decode_init,
|
|
FF_CODEC_DECODE_CB(bmv_aud_decode_frame),
|
|
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
|
|
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
|
|
};
|