yading@10: /*
yading@10:  * ADX ADPCM codecs
yading@10:  * Copyright (c) 2001,2003 BERO
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
yading@10:  */
yading@10: 
yading@10: #include "avcodec.h"
yading@10: #include "adx.h"
yading@10: #include "bytestream.h"
yading@10: #include "internal.h"
yading@10: #include "put_bits.h"
yading@10: 
yading@10: /**
yading@10:  * @file
yading@10:  * SEGA CRI adx codecs.
yading@10:  *
yading@10:  * Reference documents:
yading@10:  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
yading@10:  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
yading@10:  */
yading@10: 
yading@10: static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav,
yading@10:                        ADXChannelState *prev, int channels)
yading@10: {
yading@10:     PutBitContext pb;
yading@10:     int scale;
yading@10:     int i, j;
yading@10:     int s0, s1, s2, d;
yading@10:     int max = 0;
yading@10:     int min = 0;
yading@10:     int data[BLOCK_SAMPLES];
yading@10: 
yading@10:     s1 = prev->s1;
yading@10:     s2 = prev->s2;
yading@10:     for (i = 0, j = 0; j < 32; i += channels, j++) {
yading@10:         s0 = wav[i];
yading@10:         d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS;
yading@10:         data[j] = d;
yading@10:         if (max < d)
yading@10:             max = d;
yading@10:         if (min > d)
yading@10:             min = d;
yading@10:         s2 = s1;
yading@10:         s1 = s0;
yading@10:     }
yading@10:     prev->s1 = s1;
yading@10:     prev->s2 = s2;
yading@10: 
yading@10:     if (max == 0 && min == 0) {
yading@10:         memset(adx, 0, BLOCK_SIZE);
yading@10:         return;
yading@10:     }
yading@10: 
yading@10:     if (max / 7 > -min / 8)
yading@10:         scale = max / 7;
yading@10:     else
yading@10:         scale = -min / 8;
yading@10: 
yading@10:     if (scale == 0)
yading@10:         scale = 1;
yading@10: 
yading@10:     AV_WB16(adx, scale);
yading@10: 
yading@10:     init_put_bits(&pb, adx + 2, 16);
yading@10:     for (i = 0; i < BLOCK_SAMPLES; i++)
yading@10:         put_sbits(&pb, 4, av_clip(data[i] / scale, -8, 7));
yading@10:     flush_put_bits(&pb);
yading@10: }
yading@10: 
yading@10: #define HEADER_SIZE 36
yading@10: 
yading@10: static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
yading@10: {
yading@10:     ADXContext *c = avctx->priv_data;
yading@10: 
yading@10:     bytestream_put_be16(&buf, 0x8000);              /* header signature */
yading@10:     bytestream_put_be16(&buf, HEADER_SIZE - 4);     /* copyright offset */
yading@10:     bytestream_put_byte(&buf, 3);                   /* encoding */
yading@10:     bytestream_put_byte(&buf, BLOCK_SIZE);          /* block size */
yading@10:     bytestream_put_byte(&buf, 4);                   /* sample size */
yading@10:     bytestream_put_byte(&buf, avctx->channels);     /* channels */
yading@10:     bytestream_put_be32(&buf, avctx->sample_rate);  /* sample rate */
yading@10:     bytestream_put_be32(&buf, 0);                   /* total sample count */
yading@10:     bytestream_put_be16(&buf, c->cutoff);           /* cutoff frequency */
yading@10:     bytestream_put_byte(&buf, 3);                   /* version */
yading@10:     bytestream_put_byte(&buf, 0);                   /* flags */
yading@10:     bytestream_put_be32(&buf, 0);                   /* unknown */
yading@10:     bytestream_put_be32(&buf, 0);                   /* loop enabled */
yading@10:     bytestream_put_be16(&buf, 0);                   /* padding */
yading@10:     bytestream_put_buffer(&buf, "(c)CRI", 6);       /* copyright signature */
yading@10: 
yading@10:     return HEADER_SIZE;
yading@10: }
yading@10: 
yading@10: static av_cold int adx_encode_init(AVCodecContext *avctx)
yading@10: {
yading@10:     ADXContext *c = avctx->priv_data;
yading@10: 
yading@10:     if (avctx->channels > 2) {
yading@10:         av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10:     avctx->frame_size = BLOCK_SAMPLES;
yading@10: 
yading@10:     /* the cutoff can be adjusted, but this seems to work pretty well */
yading@10:     c->cutoff = 500;
yading@10:     ff_adx_calculate_coeffs(c->cutoff, avctx->sample_rate, COEFF_BITS, c->coeff);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
yading@10:                             const AVFrame *frame, int *got_packet_ptr)
yading@10: {
yading@10:     ADXContext *c          = avctx->priv_data;
yading@10:     const int16_t *samples = (const int16_t *)frame->data[0];
yading@10:     uint8_t *dst;
yading@10:     int ch, out_size, ret;
yading@10: 
yading@10:     out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE;
yading@10:     if ((ret = ff_alloc_packet2(avctx, avpkt, out_size)) < 0)
yading@10:         return ret;
yading@10:     dst = avpkt->data;
yading@10: 
yading@10:     if (!c->header_parsed) {
yading@10:         int hdrsize;
yading@10:         if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) {
yading@10:             av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n");
yading@10:             return AVERROR(EINVAL);
yading@10:         }
yading@10:         dst      += hdrsize;
yading@10:         c->header_parsed = 1;
yading@10:     }
yading@10: 
yading@10:     for (ch = 0; ch < avctx->channels; ch++) {
yading@10:         adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels);
yading@10:         dst += BLOCK_SIZE;
yading@10:     }
yading@10: 
yading@10:     *got_packet_ptr = 1;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: AVCodec ff_adpcm_adx_encoder = {
yading@10:     .name           = "adpcm_adx",
yading@10:     .type           = AVMEDIA_TYPE_AUDIO,
yading@10:     .id             = AV_CODEC_ID_ADPCM_ADX,
yading@10:     .priv_data_size = sizeof(ADXContext),
yading@10:     .init           = adx_encode_init,
yading@10:     .encode2        = adx_encode_frame,
yading@10:     .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
yading@10:                                                       AV_SAMPLE_FMT_NONE },
yading@10:     .long_name      = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
yading@10: };