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 "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] * (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  .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:295
const int16_t *const ff_lpc_refl_cb[10]
Definition: ra144.c:1502
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1481
AVCodec.
Definition: avcodec.h:3484
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
#define NBLOCKS
number of subblocks within a block
Definition: ra144.h:30
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2236
uint8_t
#define av_cold
Definition: attributes.h:82
av_cold void ff_audiodsp_init(AudioDSPContext *c)
Definition: audiodsp.c:106
#define FRAME_SIZE
unsigned int lpc_refl_rms[2]
Definition: ra144.h:52
#define LPC_ORDER
Definition: g723_1.h:40
unsigned int ff_rms(const int *data)
Definition: ra144.c:1636
uint8_t * data
Definition: avcodec.h:1480
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 i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#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:53
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * name
Name of the codec implementation.
Definition: avcodec.h:3491
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2279
audio channel layout utility functions
int ff_interp(RA144Context *ractx, int16_t *out, int a, int copyold, int energy)
Definition: ra144.c:1657
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
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
Libavcodec external API header.
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:677
main external API structure.
Definition: avcodec.h:1568
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1963
void * buf
Definition: avisynth_c.h:766
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:309
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:61
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:1595
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:2229
Filter the word “frame” indicates either a video frame or a group of audio samples
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:99
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: avcodec.h:1457
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:361
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:984