ffmpeg-2.1.1: move directory

git-svn-id: svn://kolibrios.org@6148 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/ffmpeg/ffmpeg-2.1/libavcodec/adxdec.c

@@ -0,0 +1,187 @@
+/*
+ * ADX ADPCM codecs
+ * Copyright (c) 2001,2003 BERO
+ *
+ * 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/intreadwrite.h"
+#include "avcodec.h"
+#include "adx.h"
+#include "get_bits.h"
+#include "internal.h"
+
+/**
+ * @file
+ * SEGA CRI adx codecs.
+ *
+ * Reference documents:
+ * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
+ * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
+ */
+
+static av_cold int adx_decode_init(AVCodecContext *avctx)
+{
+    ADXContext *c = avctx->priv_data;
+    int ret, header_size;
+
+    if (avctx->extradata_size >= 24) {
+        if ((ret = avpriv_adx_decode_header(avctx, avctx->extradata,
+                                            avctx->extradata_size, &header_size,
+                                            c->coeff)) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
+            return AVERROR_INVALIDDATA;
+        }
+        c->channels      = avctx->channels;
+        c->header_parsed = 1;
+    }
+
+    avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
+
+    return 0;
+}
+
+/**
+ * Decode 32 samples from 18 bytes.
+ *
+ * A 16-bit scalar value is applied to 32 residuals, which then have a
+ * 2nd-order LPC filter applied to it to form the output signal for a single
+ * channel.
+ */
+static int adx_decode(ADXContext *c, int16_t *out, int offset,
+                      const uint8_t *in, int ch)
+{
+    ADXChannelState *prev = &c->prev[ch];
+    GetBitContext gb;
+    int scale = AV_RB16(in);
+    int i;
+    int s0, s1, s2, d;
+
+    /* check if this is an EOF packet */
+    if (scale & 0x8000)
+        return -1;
+
+    init_get_bits(&gb, in + 2, (BLOCK_SIZE - 2) * 8);
+    out += offset;
+    s1 = prev->s1;
+    s2 = prev->s2;
+    for (i = 0; i < BLOCK_SAMPLES; i++) {
+        d  = get_sbits(&gb, 4);
+        s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
+        s2 = s1;
+        s1 = av_clip_int16(s0);
+        *out++ = s1;
+    }
+    prev->s1 = s1;
+    prev->s2 = s2;
+
+    return 0;
+}
+
+static int adx_decode_frame(AVCodecContext *avctx, void *data,
+                            int *got_frame_ptr, AVPacket *avpkt)
+{
+    AVFrame *frame      = data;
+    int buf_size        = avpkt->size;
+    ADXContext *c       = avctx->priv_data;
+    int16_t **samples;
+    int samples_offset;
+    const uint8_t *buf  = avpkt->data;
+    const uint8_t *buf_end = buf + avpkt->size;
+    int num_blocks, ch, ret;
+
+    if (c->eof) {
+        *got_frame_ptr = 0;
+        return buf_size;
+    }
+
+    if (!c->header_parsed && buf_size >= 2 && AV_RB16(buf) == 0x8000) {
+        int header_size;
+        if ((ret = avpriv_adx_decode_header(avctx, buf, buf_size, &header_size,
+                                            c->coeff)) < 0) {
+            av_log(avctx, AV_LOG_ERROR, "error parsing ADX header\n");
+            return AVERROR_INVALIDDATA;
+        }
+        c->channels      = avctx->channels;
+        c->header_parsed = 1;
+        if (buf_size < header_size)
+            return AVERROR_INVALIDDATA;
+        buf      += header_size;
+        buf_size -= header_size;
+    }
+    if (!c->header_parsed)
+        return AVERROR_INVALIDDATA;
+
+    /* calculate number of blocks in the packet */
+    num_blocks = buf_size / (BLOCK_SIZE * c->channels);
+
+    /* if the packet is not an even multiple of BLOCK_SIZE, check for an EOF
+       packet */
+    if (!num_blocks || buf_size % (BLOCK_SIZE * avctx->channels)) {
+        if (buf_size >= 4 && (AV_RB16(buf) & 0x8000)) {
+            c->eof = 1;
+            *got_frame_ptr = 0;
+            return avpkt->size;
+        }
+        return AVERROR_INVALIDDATA;
+    }
+
+    /* get output buffer */
+    frame->nb_samples = num_blocks * BLOCK_SAMPLES;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+    samples = (int16_t **)frame->extended_data;
+    samples_offset = 0;
+
+    while (num_blocks--) {
+        for (ch = 0; ch < c->channels; ch++) {
+            if (buf_end - buf < BLOCK_SIZE || adx_decode(c, samples[ch], samples_offset, buf, ch)) {
+                c->eof = 1;
+                buf = avpkt->data + avpkt->size;
+                break;
+            }
+            buf_size -= BLOCK_SIZE;
+            buf      += BLOCK_SIZE;
+        }
+        samples_offset += BLOCK_SAMPLES;
+    }
+
+    *got_frame_ptr = 1;
+
+    return buf - avpkt->data;
+}
+
+static void adx_decode_flush(AVCodecContext *avctx)
+{
+    ADXContext *c = avctx->priv_data;
+    memset(c->prev, 0, sizeof(c->prev));
+    c->eof = 0;
+}
+
+AVCodec ff_adpcm_adx_decoder = {
+    .name           = "adpcm_adx",
+    .long_name      = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_ADPCM_ADX,
+    .priv_data_size = sizeof(ADXContext),
+    .init           = adx_decode_init,
+    .decode         = adx_decode_frame,
+    .flush          = adx_decode_flush,
+    .capabilities   = CODEC_CAP_DR1,
+    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16P,
+                                                      AV_SAMPLE_FMT_NONE },
+};