FFmpeg
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 "codec_internal.h"
28 #include "decode.h"
29 #include "get_bits.h"
30 #include "ra144.h"
31 
32 
34 {
35  RA144Context *ractx = avctx->priv_data;
36 
37  ractx->avctx = avctx;
38  ff_audiodsp_init(&ractx->adsp);
39 
40  ractx->lpc_coef[0] = ractx->lpc_tables[0];
41  ractx->lpc_coef[1] = ractx->lpc_tables[1];
42 
46 
47  return 0;
48 }
49 
50 static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs,
51  int gval, GetBitContext *gb)
52 {
53  int cba_idx = get_bits(gb, 7); // index of the adaptive CB, 0 if none
54  int gain = get_bits(gb, 8);
55  int cb1_idx = get_bits(gb, 7);
56  int cb2_idx = get_bits(gb, 7);
57 
58  ff_subblock_synthesis(ractx, lpc_coefs, cba_idx, cb1_idx, cb2_idx, gval,
59  gain);
60 }
61 
62 /** Uncompress one block (20 bytes -> 160*2 bytes). */
64  int *got_frame_ptr, AVPacket *avpkt)
65 {
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 */
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] * (1 << 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  .p.name = "real_144",
131  CODEC_LONG_NAME("RealAudio 1.0 (14.4K)"),
132  .p.type = AVMEDIA_TYPE_AUDIO,
133  .p.id = AV_CODEC_ID_RA_144,
134  .priv_data_size = sizeof(RA144Context),
137  .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
138 };
do_output_subblock
static void do_output_subblock(RA144Context *ractx, const int16_t *lpc_coefs, int gval, GetBitContext *gb)
Definition: ra144dec.c:50
NBLOCKS
#define NBLOCKS
number of subblocks within a block
Definition: ra144.h:33
RA144Context::avctx
AVCodecContext * avctx
Definition: ra144.h:41
ff_energy_tab
const int16_t ff_energy_tab[32]
Definition: ra144.c:1440
FRAME_SIZE
#define FRAME_SIZE
AV_CODEC_ID_RA_144
@ AV_CODEC_ID_RA_144
Definition: codec_id.h:428
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
ff_eval_coefs
void ff_eval_coefs(int *coefs, const int *refl)
Evaluate the LPC filter coefficients from the reflection coefficients.
Definition: ra144.c:1593
AVPacket::data
uint8_t * data
Definition: packet.h:522
FFCodec
Definition: codec_internal.h:127
ff_audiodsp_init
av_cold void ff_audiodsp_init(AudioDSPContext *c)
Definition: audiodsp.c:106
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
get_bits
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:335
ra144_decode_frame
static int ra144_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)
Uncompress one block (20 bytes -> 160*2 bytes).
Definition: ra144dec.c:63
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2111
GetBitContext
Definition: get_bits.h:108
RA144Context::lpc_coef
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:53
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:545
ff_lpc_refl_cb
const int16_t *const ff_lpc_refl_cb[10]
Definition: ra144.c:1502
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
decode.h
get_bits.h
LPC_ORDER
#define LPC_ORDER
Definition: g723_1.h:40
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
frame
static AVFrame * frame
Definition: demux_decode.c:54
ff_ra_144_decoder
const FFCodec ff_ra_144_decoder
Definition: ra144dec.c:129
ff_rescale_rms
unsigned int ff_rescale_rms(unsigned int rms, unsigned int energy)
Definition: ra144.c:1678
av_clip_int16
#define av_clip_int16
Definition: common.h:113
sizes
static const int sizes[][2]
Definition: img2dec.c:58
RA144Context
Definition: ra144.h:40
RA144Context::adsp
AudioDSPContext adsp
Definition: ra144.h:42
RA144Context::lpc_tables
unsigned int lpc_tables[2][10]
Definition: ra144.h:49
AV_CODEC_CAP_CHANNEL_CONF
#define AV_CODEC_CAP_CHANNEL_CONF
Codec should fill in channel configuration and samplerate instead of container.
Definition: codec.h:106
RA144Context::curr_sblock
int16_t curr_sblock[50]
The current subblock padded by the last 10 values of the previous one.
Definition: ra144.h:60
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1618
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:365
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:523
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:313
codec_internal.h
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1084
ff_rms
unsigned int ff_rms(const int *data)
Definition: ra144.c:1636
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:420
ff_int_to_int16
void ff_int_to_int16(int16_t *out, const int *inp)
Definition: ra144.c:1613
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:255
RA144Context::old_energy
unsigned int old_energy
previous frame energy
Definition: ra144.h:47
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:58
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
ff_subblock_synthesis
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
avcodec.h
ret
ret
Definition: filter_design.txt:187
FFSWAP
#define FFSWAP(type, a, b)
Definition: macros.h:52
AVCodecContext
main external API structure.
Definition: avcodec.h:445
channel_layout.h
ff_t_sqrt
int ff_t_sqrt(unsigned int x)
Evaluate sqrt(x << 24).
Definition: ra144.c:1625
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:662
ff_interp
int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold, int energy)
Definition: ra144.c:1657
ra144.h
samples
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
AV_CHANNEL_LAYOUT_MONO
#define AV_CHANNEL_LAYOUT_MONO
Definition: channel_layout.h:388
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
ra144_decode_init
static av_cold int ra144_decode_init(AVCodecContext *avctx)
Definition: ra144dec.c:33
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
RA144Context::lpc_refl_rms
unsigned int lpc_refl_rms[2]
Definition: ra144.h:55
BLOCKSIZE
#define BLOCKSIZE
subblock size in 16-bit words
Definition: ra144.h:34