ffmpeg-2.8.5

git-svn-id: svn://kolibrios.org@6147 a494cfbc-eb01-0410-851d-a64ba20cac60

contrib/sdk/sources/ffmpeg/ffmpeg-2.8/libavcodec/g722dec.c

@@ -0,0 +1,150 @@
+/*
+ * Copyright (c) CMU 1993 Computer Science, Speech Group
+ *                        Chengxiang Lu and Alex Hauptmann
+ * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
+ * Copyright (c) 2009 Kenan Gillet
+ * Copyright (c) 2010 Martin Storsjo
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * G.722 ADPCM audio decoder
+ *
+ * This G.722 decoder is a bit-exact implementation of the ITU G.722
+ * specification for all three specified bitrates - 64000bps, 56000bps
+ * and 48000bps. It passes the ITU tests.
+ *
+ * @note For the 56000bps and 48000bps bitrates, the lowest 1 or 2 bits
+ *       respectively of each byte are ignored.
+ */
+
+#include "libavutil/channel_layout.h"
+#include "libavutil/opt.h"
+#include "avcodec.h"
+#include "get_bits.h"
+#include "g722.h"
+#include "internal.h"
+
+#define OFFSET(x) offsetof(G722Context, x)
+#define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
+static const AVOption options[] = {
+    { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_INT, { .i64 = 8 }, 6, 8, AD },
+    { NULL }
+};
+
+static const AVClass g722_decoder_class = {
+    .class_name = "g722 decoder",
+    .item_name  = av_default_item_name,
+    .option     = options,
+    .version    = LIBAVUTIL_VERSION_INT,
+};
+
+static av_cold int g722_decode_init(AVCodecContext * avctx)
+{
+    G722Context *c = avctx->priv_data;
+
+    avctx->channels       = 1;
+    avctx->channel_layout = AV_CH_LAYOUT_MONO;
+    avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
+
+    c->band[0].scale_factor = 8;
+    c->band[1].scale_factor = 2;
+    c->prev_samples_pos = 22;
+
+    ff_g722dsp_init(&c->dsp);
+
+    return 0;
+}
+
+static const int16_t low_inv_quant5[32] = {
+     -35,   -35, -2919, -2195, -1765, -1458, -1219, -1023,
+    -858,  -714,  -587,  -473,  -370,  -276,  -190,  -110,
+    2919,  2195,  1765,  1458,  1219,  1023,   858,   714,
+     587,   473,   370,   276,   190,   110,    35,   -35
+};
+
+static const int16_t * const low_inv_quants[3] = { ff_g722_low_inv_quant6,
+                                                    low_inv_quant5,
+                                            ff_g722_low_inv_quant4 };
+
+static int g722_decode_frame(AVCodecContext *avctx, void *data,
+                             int *got_frame_ptr, AVPacket *avpkt)
+{
+    G722Context *c = avctx->priv_data;
+    AVFrame *frame = data;
+    int16_t *out_buf;
+    int j, ret;
+    const int skip = 8 - c->bits_per_codeword;
+    const int16_t *quantizer_table = low_inv_quants[skip];
+    GetBitContext gb;
+
+    /* get output buffer */
+    frame->nb_samples = avpkt->size * 2;
+    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
+        return ret;
+    out_buf = (int16_t *)frame->data[0];
+
+    init_get_bits(&gb, avpkt->data, avpkt->size * 8);
+
+    for (j = 0; j < avpkt->size; j++) {
+        int ilow, ihigh, rlow, rhigh, dhigh;
+        int xout[2];
+
+        ihigh = get_bits(&gb, 2);
+        ilow = get_bits(&gb, 6 - skip);
+        skip_bits(&gb, skip);
+
+        rlow = av_clip_intp2((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
+                      + c->band[0].s_predictor, 14);
+
+        ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip));
+
+        dhigh = c->band[1].scale_factor * ff_g722_high_inv_quant[ihigh] >> 10;
+        rhigh = av_clip_intp2(dhigh + c->band[1].s_predictor, 14);
+
+        ff_g722_update_high_predictor(&c->band[1], dhigh, ihigh);
+
+        c->prev_samples[c->prev_samples_pos++] = rlow + rhigh;
+        c->prev_samples[c->prev_samples_pos++] = rlow - rhigh;
+        c->dsp.apply_qmf(c->prev_samples + c->prev_samples_pos - 24, xout);
+        *out_buf++ = av_clip_int16(xout[0] >> 11);
+        *out_buf++ = av_clip_int16(xout[1] >> 11);
+        if (c->prev_samples_pos >= PREV_SAMPLES_BUF_SIZE) {
+            memmove(c->prev_samples, c->prev_samples + c->prev_samples_pos - 22,
+                    22 * sizeof(c->prev_samples[0]));
+            c->prev_samples_pos = 22;
+        }
+    }
+
+    *got_frame_ptr = 1;
+
+    return avpkt->size;
+}
+
+AVCodec ff_adpcm_g722_decoder = {
+    .name           = "g722",
+    .long_name      = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = AV_CODEC_ID_ADPCM_G722,
+    .priv_data_size = sizeof(G722Context),
+    .init           = g722_decode_init,
+    .decode         = g722_decode_frame,
+    .capabilities   = AV_CODEC_CAP_DR1,
+    .priv_class     = &g722_decoder_class,
+};