g722: split decoder and encoder into separate files

1 files changed, 147 insertions, 0 deletions

diff --git a/libavcodec/g722dec.c b/libavcodec/g722dec.c
new file mode 100644
index 0000000..51f87c9
--- /dev/null
+++ b/libavcodec/g722dec.c
@@ -0,0 +1,147 @@
+/*
+ * 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 Libav.
+ *
+ * Libav 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.
+ *
+ * Libav 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 Libav; 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 "avcodec.h"
+#include "get_bits.h"
+#include "g722.h"
+
+static av_cold int g722_decode_init(AVCodecContext * avctx)
+{
+    G722Context *c = avctx->priv_data;
+
+    if (avctx->channels != 1) {
+        av_log(avctx, AV_LOG_ERROR, "Only mono tracks are allowed.\n");
+        return AVERROR_INVALIDDATA;
+    }
+    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
+
+    switch (avctx->bits_per_coded_sample) {
+    case 8:
+    case 7:
+    case 6:
+        break;
+    default:
+        av_log(avctx, AV_LOG_WARNING, "Unsupported bits_per_coded_sample [%d], "
+                                      "assuming 8\n",
+                                      avctx->bits_per_coded_sample);
+    case 0:
+        avctx->bits_per_coded_sample = 8;
+        break;
+    }
+
+    c->band[0].scale_factor = 8;
+    c->band[1].scale_factor = 2;
+    c->prev_samples_pos = 22;
+
+    if (avctx->lowres)
+        avctx->sample_rate /= 2;
+
+    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 *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 *data_size, AVPacket *avpkt)
+{
+    G722Context *c = avctx->priv_data;
+    int16_t *out_buf = data;
+    int j, out_len = 0;
+    const int skip = 8 - avctx->bits_per_coded_sample;
+    const int16_t *quantizer_table = low_inv_quants[skip];
+    GetBitContext gb;
+
+    init_get_bits(&gb, avpkt->data, avpkt->size * 8);
+
+    for (j = 0; j < avpkt->size; j++) {
+        int ilow, ihigh, rlow;
+
+        ihigh = get_bits(&gb, 2);
+        ilow = get_bits(&gb, 6 - skip);
+        skip_bits(&gb, skip);
+
+        rlow = av_clip((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
+                      + c->band[0].s_predictor, -16384, 16383);
+
+        ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip));
+
+        if (!avctx->lowres) {
+            const int dhigh = c->band[1].scale_factor *
+                              ff_g722_high_inv_quant[ihigh] >> 10;
+            const int rhigh = av_clip(dhigh + c->band[1].s_predictor,
+                                      -16384, 16383);
+            int xout1, xout2;
+
+            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;
+            ff_g722_apply_qmf(c->prev_samples + c->prev_samples_pos - 24,
+                              &xout1, &xout2);
+            out_buf[out_len++] = av_clip_int16(xout1 >> 12);
+            out_buf[out_len++] = av_clip_int16(xout2 >> 12);
+            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;
+            }
+        } else
+            out_buf[out_len++] = rlow;
+    }
+    *data_size = out_len << 1;
+    return avpkt->size;
+}
+
+AVCodec ff_adpcm_g722_decoder = {
+    .name           = "g722",
+    .type           = AVMEDIA_TYPE_AUDIO,
+    .id             = CODEC_ID_ADPCM_G722,
+    .priv_data_size = sizeof(G722Context),
+    .init           = g722_decode_init,
+    .decode         = g722_decode_frame,
+    .long_name      = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
+    .max_lowres     = 1,
+};