ra144dec.c
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1 /*
2  * Real Audio 1.0 (14.4K)
3  *
4  * Copyright (c) 2008 Vitor Sessak
5  * Copyright (c) 2003 Nick Kurshev
6  * Based on public domain decoder at http://www.honeypot.net/audio
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 
26 #include "libavutil/intmath.h"
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "internal.h"
30 #include "ra144.h"
31 
32 
34 {
35  RA144Context *ractx = avctx->priv_data;
36 
37  ractx->avctx = avctx;
38 
39  ractx->lpc_coef[0] = ractx->lpc_tables[0];
40  ractx->lpc_coef[1] = ractx->lpc_tables[1];
41 
42  avctx->channels = 1;
45 
47  avctx->coded_frame = &ractx->frame;
48 
49  return 0;
50 }
51 
52 static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs,
53  int gval, GetBitContext *gb)
54 {
55  int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
56  int gain = get_bits(gb, 8);
57  int cb1_idx = get_bits(gb, 7);
58  int cb2_idx = get_bits(gb, 7);
59 
60  ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
61  gain);
62 }
63 
65 static int ra144_decode_frame(AVCodecContext * avctx, void *data,
66  int *got_frame_ptr, AVPacket *avpkt)
67 {
68  const uint8_t *buf = avpkt->data;
69  int buf_size = avpkt->size;
70  static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
71  unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients
72  uint16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block
73  unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame
74  int i, j;
75  int ret;
76  int16_t *samples;
77  unsigned int energy;
78 
79  RA144Context *ractx = avctx->priv_data;
80  GetBitContext gb;
81 
82  /* get output buffer */
83  ractx->frame.nb_samples = NBLOCKS * BLOCKSIZE;
84  if ((ret = ff_get_buffer(avctx, &ractx->frame)) < 0) {
85  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
86  return ret;
87  }
88  samples = (int16_t *)ractx->frame.data[0];
89 
90  if(buf_size < FRAMESIZE) {
91  av_log(avctx, AV_LOG_ERROR,
92  "Frame too small (%d bytes). Truncated file?\n", buf_size);
93  *got_frame_ptr = 0;
94  return buf_size;
95  }
96  init_get_bits(&gb, buf, FRAMESIZE * 8);
97 
98  for (i = 0; i < LPC_ORDER; i++)
99  lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];
100 
101  ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
102  ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
103 
104  energy = ff_energy_tab[get_bits(&gb, 5)];
105 
106  refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
107  refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
108  energy <= ractx->old_energy,
109  ff_t_sqrt(energy*ractx->old_energy) >> 12);
110  refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
111  refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
112 
113  ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
114 
115  for (i=0; i < NBLOCKS; i++) {
116  do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
117 
118  for (j=0; j < BLOCKSIZE; j++)
119  *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
120  }
121 
122  ractx->old_energy = energy;
123  ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
124 
125  FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
126 
127  *got_frame_ptr = 1;
128  *(AVFrame *)data = ractx->frame;
129 
130  return FRAMESIZE;
131 }
132 
134  .name = "real_144",
135  .type = AVMEDIA_TYPE_AUDIO,
136  .id = AV_CODEC_ID_RA_144,
137  .priv_data_size = sizeof(RA144Context),
140  .capabilities = CODEC_CAP_DR1,
141  .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
142 };
unsigned int lpc_tables[2][10]
Definition: ra144.h:45
static int16_t * samples
int ff_t_sqrt(unsigned int x)
Evaluate sqrt(x << 24).
Definition: ra144.c:1618
This structure describes decoded (raw) audio or video data.
Definition: avcodec.h:989
const int16_t *const ff_lpc_refl_cb[10]
Definition: ra144.c:1502
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2725
int size
Definition: avcodec.h:916
signed 16 bits
Definition: samplefmt.h:52
AVCodec.
Definition: avcodec.h:2960
#define NBLOCKS
number of subblocks within a block
Definition: ra144.h:29
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:228
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2112
uint8_t
unsigned int lpc_refl_rms[2]
Definition: ra144.h:51
unsigned int ff_rms(const int *data)
Definition: ra144.c:1629
const char data[16]
Definition: mxf.c:66
uint8_t * data
Definition: avcodec.h:915
bitstream reader API header.
#define FRAMESIZE
size of encoded frame
Definition: ra144.h:33
void ff_subblock_synthesis(RA144Context *ractx, const uint16_t *lpc_coefs, int cba_idx, int cb1_idx, int cb2_idx, int gval, int gain)
Definition: ra144.c:1690
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:335
AVCodecContext * avctx
Definition: ra144.h:37
static av_cold int ra144_decode_init(AVCodecContext *avctx)
Definition: ra144dec.c:33
unsigned int * lpc_coef[2]
LPC coefficients: lpc_coef[0] is the coefficients of the current frame and lpc_coef[1] of the previou...
Definition: ra144.h:49
static const int sizes[][2]
Definition: img2dec.c:46
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:88
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:146
const char * name
Name of the codec implementation.
Definition: avcodec.h:2967
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2165
audio channel layout utility functions
int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold, int energy)
Definition: ra144.c:1650
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame)
Get a buffer for a frame.
Definition: utils.c:464
AVFrame frame
Definition: ra144.h:38
void ff_int_to_int16(int16_t *out, const int *inp)
Definition: ra144.c:1606
#define BLOCKSIZE
subblock size in 16-bit words
Definition: ra144.h:30
void ff_eval_coefs(int *coefs, const int *refl)
Evaluate the LPC filter coefficients from the reflection coefficients.
Definition: ra144.c:1586
external API header
main external API structure.
Definition: avcodec.h:1339
struct RA144Context RA144Context
void avcodec_get_frame_defaults(AVFrame *frame)
Set the fields of the given AVFrame to default values.
Definition: utils.c:604
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:372
AVCodec ff_ra_144_decoder
Definition: ra144dec.c:133
unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy)
Definition: ra144.c:1671
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
#define LPC_ORDER
Definition: g723_1_data.h:36
common internal api header.
unsigned int old_energy
previous frame energy
Definition: ra144.h:43
const int16_t ff_energy_tab[32]
Definition: ra144.c:1440
int16_t curr_sblock[50]
The current subblock padded by the last 10 values of the previous one.
Definition: ra144.h:56
static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs, int gval, GetBitContext *gb)
Definition: ra144dec.c:52
void * priv_data
Definition: avcodec.h:1382
int channels
number of audio channels
Definition: avcodec.h:2105
static int ra144_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Uncompress one block (20 bytes -> 160*2 bytes).
Definition: ra144dec.c:65
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:898
int nb_samples
number of audio samples (per channel) described by this frame
Definition: avcodec.h:1042