Libav
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 "avcodec.h"
27 #include "get_bits.h"
28 #include "internal.h"
29 #include "ra144.h"
30 
31 
33 {
34  RA144Context *ractx = avctx->priv_data;
35 
36  ractx->avctx = avctx;
37 
38  ractx->lpc_coef[0] = ractx->lpc_tables[0];
39  ractx->lpc_coef[1] = ractx->lpc_tables[1];
40 
41  avctx->channels = 1;
44 
45  return 0;
46 }
47 
48 static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs,
49  int gval, GetBitContext *gb)
50 {
51  int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
52  int gain = get_bits(gb, 8);
53  int cb1_idx = get_bits(gb, 7);
54  int cb2_idx = get_bits(gb, 7);
55 
56  ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
57  gain);
58 }
59 
61 static int ra144_decode_frame(AVCodecContext * avctx, void *data,
62  int *got_frame_ptr, AVPacket *avpkt)
63 {
64  AVFrame *frame = data;
65  const uint8_t *buf = avpkt->data;
66  int buf_size = avpkt->size;
67  static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
68  unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients
69  uint16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block
70  unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame
71  int i, j;
72  int ret;
73  int16_t *samples;
74  unsigned int energy;
75 
76  RA144Context *ractx = avctx->priv_data;
77  GetBitContext gb;
78 
79  if (buf_size < FRAMESIZE) {
80  av_log(avctx, AV_LOG_ERROR,
81  "Frame too small (%d bytes). Truncated file?\n", buf_size);
82  *got_frame_ptr = 0;
83  return AVERROR_INVALIDDATA;
84  }
85 
86  /* get output buffer */
87  frame->nb_samples = NBLOCKS * BLOCKSIZE;
88  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
89  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
90  return ret;
91  }
92  samples = (int16_t *)frame->data[0];
93 
94  init_get_bits(&gb, buf, FRAMESIZE * 8);
95 
96  for (i = 0; i < LPC_ORDER; i++)
97  lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];
98 
99  ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
100  ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
101 
102  energy = ff_energy_tab[get_bits(&gb, 5)];
103 
104  refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
105  refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
106  energy <= ractx->old_energy,
107  ff_t_sqrt(energy*ractx->old_energy) >> 12);
108  refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
109  refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
110 
111  ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
112 
113  for (i=0; i < NBLOCKS; i++) {
114  do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
115 
116  for (j=0; j < BLOCKSIZE; j++)
117  *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
118  }
119 
120  ractx->old_energy = energy;
121  ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
122 
123  FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
124 
125  *got_frame_ptr = 1;
126 
127  return FRAMESIZE;
128 }
129 
131  .name = "real_144",
132  .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
133  .type = AVMEDIA_TYPE_AUDIO,
134  .id = AV_CODEC_ID_RA_144,
135  .priv_data_size = sizeof(RA144Context),
138  .capabilities = CODEC_CAP_DR1,
139 };
unsigned int lpc_tables[2][10]
Definition: ra144.h:44
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
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: frame.h:135
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:240
int size
Definition: avcodec.h:974
AVCodec.
Definition: avcodec.h:2796
#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:275
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1799
uint8_t
#define av_cold
Definition: attributes.h:66
unsigned int lpc_refl_rms[2]
Definition: ra144.h:50
unsigned int ff_rms(const int *data)
Definition: ra144.c:1629
#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
uint8_t * data
Definition: avcodec.h:973
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
AVCodecContext * avctx
Definition: ra144.h:37
static av_cold int ra144_decode_init(AVCodecContext *avctx)
Definition: ra144dec.c:32
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
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:48
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:150
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:168
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1852
audio channel layout utility functions
int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold, int energy)
Definition: ra144.c:1650
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
Libavcodec external API header.
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
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
AVCodec ff_ra_144_decoder
Definition: ra144dec.c:130
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: frame.h:141
#define LPC_ORDER
Definition: g723_1_data.h:36
common internal api header.
unsigned int old_energy
previous frame energy
Definition: ra144.h:42
const int16_t ff_energy_tab[32]
Definition: ra144.c:1440
signed 16 bits
Definition: samplefmt.h:64
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
int16_t curr_sblock[50]
The current subblock padded by the last 10 values of the previous one.
Definition: ra144.h:55
static void do_output_subblock(RA144Context *ractx, const uint16_t *lpc_coefs, int gval, GetBitContext *gb)
Definition: ra144dec.c:48
void * priv_data
Definition: avcodec.h:1092
int channels
number of audio channels
Definition: avcodec.h:1792
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:61
#define FFSWAP(type, a, b)
Definition: common.h:60
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:950
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:179