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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 FFmpeg.
9  *
10  * FFmpeg 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  * FFmpeg 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 FFmpeg; 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  ff_audiodsp_init(&ractx->adsp);
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 
46  return 0;
47 }
48 
49 static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs,
50  int gval, GetBitContext *gb)
51 {
52  int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
53  int gain = get_bits(gb, 8);
54  int cb1_idx = get_bits(gb, 7);
55  int cb2_idx = get_bits(gb, 7);
56 
57  ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
58  gain);
59 }
60 
61 /** Uncompress one block (20 bytes -> 160*2 bytes). */
62 static int ra144_decode_frame(AVCodecContext * avctx, void *data,
63  int *got_frame_ptr, AVPacket *avpkt)
64 {
65  AVFrame *frame = data;
66  const uint8_t *buf = avpkt->data;
67  int buf_size = avpkt->size;
68  static const uint8_t sizes[LPC_ORDER] = {6, 5, 5, 4, 4, 3, 3, 3, 3, 2};
69  unsigned int refl_rms[NBLOCKS]; // RMS of the reflection coefficients
70  int16_t block_coefs[NBLOCKS][LPC_ORDER]; // LPC coefficients of each sub-block
71  unsigned int lpc_refl[LPC_ORDER]; // LPC reflection coefficients of the frame
72  int i, j;
73  int ret;
74  int16_t *samples;
75  unsigned int energy;
76 
77  RA144Context *ractx = avctx->priv_data;
78  GetBitContext gb;
79 
80  if (buf_size < FRAME_SIZE) {
81  av_log(avctx, AV_LOG_ERROR,
82  "Frame too small (%d bytes). Truncated file?\n", buf_size);
83  *got_frame_ptr = 0;
84  return AVERROR_INVALIDDATA;
85  }
86 
87  /* get output buffer */
88  frame->nb_samples = NBLOCKS * BLOCKSIZE;
89  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
90  return ret;
91  samples = (int16_t *)frame->data[0];
92 
93  init_get_bits8(&gb, buf, FRAME_SIZE);
94 
95  for (i = 0; i < LPC_ORDER; i++)
96  lpc_refl[i] = ff_lpc_refl_cb[i][get_bits(&gb, sizes[i])];
97 
98  ff_eval_coefs(ractx->lpc_coef[0], lpc_refl);
99  ractx->lpc_refl_rms[0] = ff_rms(lpc_refl);
100 
101  energy = ff_energy_tab[get_bits(&gb, 5)];
102 
103  refl_rms[0] = ff_interp(ractx, block_coefs[0], 1, 1, ractx->old_energy);
104  refl_rms[1] = ff_interp(ractx, block_coefs[1], 2,
105  energy <= ractx->old_energy,
106  ff_t_sqrt(energy*ractx->old_energy) >> 12);
107  refl_rms[2] = ff_interp(ractx, block_coefs[2], 3, 0, energy);
108  refl_rms[3] = ff_rescale_rms(ractx->lpc_refl_rms[0], energy);
109 
110  ff_int_to_int16(block_coefs[3], ractx->lpc_coef[0]);
111 
112  for (i=0; i < NBLOCKS; i++) {
113  do_output_subblock(ractx, block_coefs[i], refl_rms[i], &gb);
114 
115  for (j=0; j < BLOCKSIZE; j++)
116  *samples++ = av_clip_int16(ractx->curr_sblock[j + 10] << 2);
117  }
118 
119  ractx->old_energy = energy;
120  ractx->lpc_refl_rms[1] = ractx->lpc_refl_rms[0];
121 
122  FFSWAP(unsigned int *, ractx->lpc_coef[0], ractx->lpc_coef[1]);
123 
124  *got_frame_ptr = 1;
125 
126  return FRAME_SIZE;
127 }
128 
130  .name = "real_144",
131  .long_name = NULL_IF_CONFIG_SMALL("RealAudio 1.0 (14.4K)"),
132  .type = AVMEDIA_TYPE_AUDIO,
133  .id = AV_CODEC_ID_RA_144,
134  .priv_data_size = sizeof(RA144Context),
137  .capabilities = AV_CODEC_CAP_DR1,
138 };
unsigned int lpc_tables[2][10]
Definition: ra144.h:46
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int ff_t_sqrt(unsigned int x)
Evaluate sqrt(x << 24).
Definition: ra144.c:1625
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
const int16_t *const ff_lpc_refl_cb[10]
Definition: ra144.c:1502
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:260
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1424
av_cold void ff_audiodsp_init(AudioDSPContext *c)
Definition: audiodsp.c:106
AVCodec.
Definition: avcodec.h:3472
#define NBLOCKS
number of subblocks within a block
Definition: ra144.h:30
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2270
uint8_t
#define av_cold
Definition: attributes.h:74
#define FRAME_SIZE
unsigned int lpc_refl_rms[2]
Definition: ra144.h:52
unsigned int ff_rms(const int *data)
Definition: ra144.c:1636
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1423
bitstream reader API header.
#define av_log(a,...)
AVCodecContext * avctx
Definition: ra144.h:38
void ff_subblock_synthesis(RA144Context *ractx, const int16_t *lpc_coefs, int cba_idx, int cb1_idx, int cb2_idx, int gval, int gain)
Definition: ra144.c:1694
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:176
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:50
static const int sizes[][2]
Definition: img2dec.c:48
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:175
const char * name
Name of the codec implementation.
Definition: avcodec.h:3479
Libavcodec external API header.
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2323
audio channel layout utility functions
int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold, int energy)
Definition: ra144.c:1657
void ff_int_to_int16(int16_t *out, const int *inp)
Definition: ra144.c:1613
#define BLOCKSIZE
subblock size in 16-bit words
Definition: ra144.h:31
void ff_eval_coefs(int *coefs, const int *refl)
Evaluate the LPC filter coefficients from the reflection coefficients.
Definition: ra144.c:1593
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:441
main external API structure.
Definition: avcodec.h:1502
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:1040
void * buf
Definition: avisynth_c.h:553
AVCodec ff_ra_144_decoder
Definition: ra144dec.c:129
unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy)
Definition: ra144.c:1678
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:182
#define LPC_ORDER
Definition: g723_1_data.h:38
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:523
AudioDSPContext adsp
Definition: ra144.h:39
common internal api header.
unsigned int old_energy
previous frame energy
Definition: ra144.h:44
const int16_t ff_energy_tab[32]
Definition: ra144.c:1440
signed 16 bits
Definition: samplefmt.h:62
int16_t curr_sblock[50]
The current subblock padded by the last 10 values of the previous one.
Definition: ra144.h:57
void * priv_data
Definition: avcodec.h:1544
static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs, int gval, GetBitContext *gb)
Definition: ra144dec.c:49
int channels
number of audio channels
Definition: avcodec.h:2263
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:62
#define FFSWAP(type, a, b)
Definition: common.h:69
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:1400
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:225
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:857