Libav
g722dec.c
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1 /*
2  * Copyright (c) CMU 1993 Computer Science, Speech Group
3  * Chengxiang Lu and Alex Hauptmann
4  * Copyright (c) 2005 Steve Underwood <steveu at coppice.org>
5  * Copyright (c) 2009 Kenan Gillet
6  * Copyright (c) 2010 Martin Storsjo
7  *
8  * This file is part of Libav.
9  *
10  * Libav is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * Libav is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with Libav; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
37 #include "libavutil/channel_layout.h"
38 #include "libavutil/opt.h"
39 #include "avcodec.h"
40 #include "get_bits.h"
41 #include "g722.h"
42 #include "internal.h"
43 
44 #define OFFSET(x) offsetof(G722Context, x)
45 #define AD AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM
46 static const AVOption options[] = {
47  { "bits_per_codeword", "Bits per G722 codeword", OFFSET(bits_per_codeword), AV_OPT_TYPE_INT, { .i64 = 8 }, 6, 8, AD },
48  { NULL }
49 };
50 
51 static const AVClass g722_decoder_class = {
52  .class_name = "g722 decoder",
53  .item_name = av_default_item_name,
54  .option = options,
55  .version = LIBAVUTIL_VERSION_INT,
56 };
57 
59 {
60  G722Context *c = avctx->priv_data;
61 
62  avctx->channels = 1;
65 
66  c->band[0].scale_factor = 8;
67  c->band[1].scale_factor = 2;
68  c->prev_samples_pos = 22;
69 
70  return 0;
71 }
72 
73 static const int16_t low_inv_quant5[32] = {
74  -35, -35, -2919, -2195, -1765, -1458, -1219, -1023,
75  -858, -714, -587, -473, -370, -276, -190, -110,
76  2919, 2195, 1765, 1458, 1219, 1023, 858, 714,
77  587, 473, 370, 276, 190, 110, 35, -35
78 };
79 
80 static const int16_t *low_inv_quants[3] = { ff_g722_low_inv_quant6,
83 
84 static int g722_decode_frame(AVCodecContext *avctx, void *data,
85  int *got_frame_ptr, AVPacket *avpkt)
86 {
87  G722Context *c = avctx->priv_data;
88  AVFrame *frame = data;
89  int16_t *out_buf;
90  int j, ret;
91  const int skip = 8 - c->bits_per_codeword;
92  const int16_t *quantizer_table = low_inv_quants[skip];
93  GetBitContext gb;
94 
95  /* get output buffer */
96  frame->nb_samples = avpkt->size * 2;
97  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
98  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
99  return ret;
100  }
101  out_buf = (int16_t *)frame->data[0];
102 
103  init_get_bits(&gb, avpkt->data, avpkt->size * 8);
104 
105  for (j = 0; j < avpkt->size; j++) {
106  int ilow, ihigh, rlow, rhigh, dhigh;
107  int xout1, xout2;
108 
109  ihigh = get_bits(&gb, 2);
110  ilow = get_bits(&gb, 6 - skip);
111  skip_bits(&gb, skip);
112 
113  rlow = av_clip((c->band[0].scale_factor * quantizer_table[ilow] >> 10)
114  + c->band[0].s_predictor, -16384, 16383);
115 
116  ff_g722_update_low_predictor(&c->band[0], ilow >> (2 - skip));
117 
118  dhigh = c->band[1].scale_factor * ff_g722_high_inv_quant[ihigh] >> 10;
119  rhigh = av_clip(dhigh + c->band[1].s_predictor, -16384, 16383);
120 
121  ff_g722_update_high_predictor(&c->band[1], dhigh, ihigh);
122 
123  c->prev_samples[c->prev_samples_pos++] = rlow + rhigh;
124  c->prev_samples[c->prev_samples_pos++] = rlow - rhigh;
126  &xout1, &xout2);
127  *out_buf++ = av_clip_int16(xout1 >> 11);
128  *out_buf++ = av_clip_int16(xout2 >> 11);
130  memmove(c->prev_samples, c->prev_samples + c->prev_samples_pos - 22,
131  22 * sizeof(c->prev_samples[0]));
132  c->prev_samples_pos = 22;
133  }
134  }
135 
136  *got_frame_ptr = 1;
137 
138  return avpkt->size;
139 }
140 
142  .name = "g722",
143  .long_name = NULL_IF_CONFIG_SMALL("G.722 ADPCM"),
144  .type = AVMEDIA_TYPE_AUDIO,
146  .priv_data_size = sizeof(G722Context),
149  .capabilities = CODEC_CAP_DR1,
150  .priv_class = &g722_decoder_class,
151 };
#define OFFSET(x)
Definition: g722dec.c:44
const int16_t ff_g722_low_inv_quant4[16]
Definition: g722.c:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
AVOption.
Definition: opt.h:234
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
AVCodec ff_adpcm_g722_decoder
Definition: g722dec.c:141
int size
Definition: avcodec.h:974
void av_log(void *avcl, int level, const char *fmt,...) av_printf_format(3
Send the specified message to the log if the level is less than or equal to the current av_log_level...
static av_cold int g722_decode_init(AVCodecContext *avctx)
Definition: g722dec.c:58
AVCodec.
Definition: avcodec.h:2796
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1799
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:38
#define PREV_SAMPLES_BUF_SIZE
Definition: g722.h:31
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
bitstream reader API header.
static const AVClass g722_decoder_class
Definition: g722dec.c:51
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
int bits_per_codeword
Definition: g722.h:35
const int16_t ff_g722_low_inv_quant6[64]
Definition: g722.c:63
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
void ff_g722_apply_qmf(const int16_t *prev_samples, int *xout1, int *xout2)
Definition: g722.c:161
int16_t prev_samples[PREV_SAMPLES_BUF_SIZE]
memory of past decoded samples
Definition: g722.h:36
Libavcodec external API header.
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1852
struct G722Context::G722Band band[2]
static const AVOption options[]
Definition: g722dec.c:46
void ff_g722_update_low_predictor(struct G722Band *band, const int ilow)
Definition: g722.c:139
LIBAVUTIL_VERSION_INT
Definition: eval.c:55
static const int16_t low_inv_quant5[32]
Definition: g722dec.c:73
NULL
Definition: eval.c:55
#define av_cold
Definition: attributes.h:66
#define AD
Definition: g722dec.c:45
main external API structure.
Definition: avcodec.h:1050
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:612
Describe the class of an AVClass context structure.
Definition: log.h:33
static void skip_bits(GetBitContext *s, int n)
Definition: get_bits.h:263
uint8_t * data
Definition: avcodec.h:973
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
static const int16_t * low_inv_quants[3]
Definition: g722dec.c:80
void * priv_data
Definition: avcodec.h:1092
common internal api header.
signed 16 bits
Definition: samplefmt.h:64
int prev_samples_pos
the number of values in prev_samples
Definition: g722.h:37
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
static int g722_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: g722dec.c:84
const int16_t ff_g722_high_inv_quant[4]
Definition: g722.c:51
int channels
number of audio channels
Definition: avcodec.h:1792
int16_t s_predictor
predictor output value
Definition: g722.h:43
void ff_g722_update_high_predictor(struct G722Band *band, const int dhigh, const int ihigh)
Definition: g722.c:150
av_default_item_name
Return the context name.
Definition: dnxhdenc.c:52
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:950
int16_t scale_factor
delayed quantizer scale factor
Definition: g722.h:51
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:179
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141