diff options
| author | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:57:22 +0100 |
|---|---|---|
| committer | Tim Redfern <tim@eclectronics.org> | 2013-09-05 17:57:22 +0100 |
| commit | 8992cb1d0d07edc33d274f6d7924ecdf6f83d994 (patch) | |
| tree | 3a2c86846b7eec8137c1507e623fc7018f13d453 /ffmpeg/libavcodec/ws-snd1.c | |
| parent | 741fb4b9e135cfb161a749db88713229038577bb (diff) | |
making act segmenter
Diffstat (limited to 'ffmpeg/libavcodec/ws-snd1.c')
| -rw-r--r-- | ffmpeg/libavcodec/ws-snd1.c | 181 |
1 files changed, 181 insertions, 0 deletions
diff --git a/ffmpeg/libavcodec/ws-snd1.c b/ffmpeg/libavcodec/ws-snd1.c new file mode 100644 index 0000000..d27df75 --- /dev/null +++ b/ffmpeg/libavcodec/ws-snd1.c @@ -0,0 +1,181 @@ +/* + * Westwood SNDx codecs + * Copyright (c) 2005 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 <stdint.h> + +#include "libavutil/channel_layout.h" +#include "libavutil/common.h" +#include "libavutil/intreadwrite.h" +#include "avcodec.h" +#include "internal.h" + +/** + * @file + * Westwood SNDx codecs + * + * Reference documents about VQA format and its audio codecs + * can be found here: + * http://www.multimedia.cx + */ + +static const int8_t ws_adpcm_4bit[] = { + -9, -8, -6, -5, -4, -3, -2, -1, + 0, 1, 2, 3, 4, 5, 6, 8 +}; + +static av_cold int ws_snd_decode_init(AVCodecContext *avctx) +{ + avctx->channels = 1; + avctx->channel_layout = AV_CH_LAYOUT_MONO; + avctx->sample_fmt = AV_SAMPLE_FMT_U8; + + return 0; +} + +static int ws_snd_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 in_size, out_size, ret; + int sample = 128; + uint8_t *samples; + uint8_t *samples_end; + + if (!buf_size) + return 0; + + if (buf_size < 4) { + av_log(avctx, AV_LOG_ERROR, "packet is too small\n"); + return AVERROR(EINVAL); + } + + out_size = AV_RL16(&buf[0]); + in_size = AV_RL16(&buf[2]); + buf += 4; + + if (in_size > buf_size) { + av_log(avctx, AV_LOG_ERROR, "Frame data is larger than input buffer\n"); + return AVERROR_INVALIDDATA; + } + + /* get output buffer */ + frame->nb_samples = out_size; + if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) + return ret; + samples = frame->data[0]; + samples_end = samples + out_size; + + if (in_size == out_size) { + memcpy(samples, buf, out_size); + *got_frame_ptr = 1; + return buf_size; + } + + while (samples < samples_end && buf - avpkt->data < buf_size) { + int code, smp, size; + uint8_t count; + code = *buf >> 6; + count = *buf & 0x3F; + buf++; + + /* make sure we don't write past the output buffer */ + switch (code) { + case 0: smp = 4 * (count + 1); break; + case 1: smp = 2 * (count + 1); break; + case 2: smp = (count & 0x20) ? 1 : count + 1; break; + default: smp = count + 1; break; + } + if (samples_end - samples < smp) + break; + + /* make sure we don't read past the input buffer */ + size = ((code == 2 && (count & 0x20)) || code == 3) ? 0 : count + 1; + if ((buf - avpkt->data) + size > buf_size) + break; + + switch (code) { + case 0: /* ADPCM 2-bit */ + for (count++; count > 0; count--) { + code = *buf++; + sample += ( code & 0x3) - 2; + sample = av_clip_uint8(sample); + *samples++ = sample; + sample += ((code >> 2) & 0x3) - 2; + sample = av_clip_uint8(sample); + *samples++ = sample; + sample += ((code >> 4) & 0x3) - 2; + sample = av_clip_uint8(sample); + *samples++ = sample; + sample += (code >> 6) - 2; + sample = av_clip_uint8(sample); + *samples++ = sample; + } + break; + case 1: /* ADPCM 4-bit */ + for (count++; count > 0; count--) { + code = *buf++; + sample += ws_adpcm_4bit[code & 0xF]; + sample = av_clip_uint8(sample); + *samples++ = sample; + sample += ws_adpcm_4bit[code >> 4]; + sample = av_clip_uint8(sample); + *samples++ = sample; + } + break; + case 2: /* no compression */ + if (count & 0x20) { /* big delta */ + int8_t t; + t = count; + t <<= 3; + sample += t >> 3; + sample = av_clip_uint8(sample); + *samples++ = sample; + } else { /* copy */ + memcpy(samples, buf, smp); + samples += smp; + buf += smp; + sample = buf[-1]; + } + break; + default: /* run */ + memset(samples, sample, smp); + samples += smp; + } + } + + frame->nb_samples = samples - frame->data[0]; + *got_frame_ptr = 1; + + return buf_size; +} + +AVCodec ff_ws_snd1_decoder = { + .name = "ws_snd1", + .type = AVMEDIA_TYPE_AUDIO, + .id = AV_CODEC_ID_WESTWOOD_SND1, + .init = ws_snd_decode_init, + .decode = ws_snd_decode_frame, + .capabilities = CODEC_CAP_DR1, + .long_name = NULL_IF_CONFIG_SMALL("Westwood Audio (SND1)"), +}; |
