FFmpeg
8svx.c
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1 /*
2  * Copyright (C) 2008 Jaikrishnan Menon
3  * Copyright (C) 2011 Stefano Sabatini
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * 8svx audio decoder
25  * @author Jaikrishnan Menon
26  *
27  * supports: fibonacci delta encoding
28  * : exponential encoding
29  *
30  * For more information about the 8SVX format:
31  * http://netghost.narod.ru/gff/vendspec/iff/iff.txt
32  * http://sox.sourceforge.net/AudioFormats-11.html
33  * http://aminet.net/package/mus/misc/wavepak
34  * http://amigan.1emu.net/reg/8SVX.txt
35  *
36  * Samples can be found here:
37  * http://aminet.net/mods/smpl/
38  */
39 
40 #include "config_components.h"
41 
42 #include "libavutil/avassert.h"
43 #include "libavutil/mem.h"
44 #include "avcodec.h"
45 #include "codec_internal.h"
46 #include "decode.h"
47 #include "libavutil/common.h"
48 
49 /** decoder context */
50 typedef struct EightSvxContext {
51  uint8_t fib_acc[2];
52  const int8_t *table;
53 
54  /* buffer used to store the whole first packet.
55  data is only sent as one large packet */
56  uint8_t *data[2];
57  int data_size;
58  int data_idx;
60 
61 static const int8_t fibonacci[16] = { -34, -21, -13, -8, -5, -3, -2, -1, 0, 1, 2, 3, 5, 8, 13, 21 };
62 static const int8_t exponential[16] = { -128, -64, -32, -16, -8, -4, -2, -1, 0, 1, 2, 4, 8, 16, 32, 64 };
63 
64 #define MAX_FRAME_SIZE 2048
65 
66 /**
67  * Delta decode the compressed values in src, and put the resulting
68  * decoded samples in dst.
69  *
70  * @param[in,out] state starting value. it is saved for use in the next call.
71  * @param table delta sequence table
72  */
73 static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size,
74  uint8_t *state, const int8_t *table)
75 {
76  uint8_t val = *state;
77 
78  while (src_size--) {
79  uint8_t d = *src++;
80  val = av_clip_uint8(val + table[d & 0xF]);
81  *dst++ = val;
82  val = av_clip_uint8(val + table[d >> 4]);
83  *dst++ = val;
84  }
85 
86  *state = val;
87 }
88 
89 /** decode a frame */
91  int *got_frame_ptr, AVPacket *avpkt)
92 {
93  EightSvxContext *esc = avctx->priv_data;
94  int channels = avctx->ch_layout.nb_channels;
95  int buf_size;
96  int ch, ret;
97  int hdr_size = 2;
98 
99  /* decode and interleave the first packet */
100  if (!esc->data[0] && avpkt) {
101  int chan_size = avpkt->size / channels - hdr_size;
102 
103  if (avpkt->size % channels) {
104  av_log(avctx, AV_LOG_WARNING, "Packet with odd size, ignoring last byte\n");
105  }
106  if (avpkt->size < (hdr_size + 1) * channels) {
107  av_log(avctx, AV_LOG_ERROR, "packet size is too small\n");
108  return AVERROR_INVALIDDATA;
109  }
110 
111  esc->fib_acc[0] = avpkt->data[1] + 128;
112  if (channels == 2)
113  esc->fib_acc[1] = avpkt->data[2+chan_size+1] + 128;
114 
115  esc->data_idx = 0;
116  esc->data_size = chan_size;
117  if (!(esc->data[0] = av_malloc(chan_size)))
118  return AVERROR(ENOMEM);
119  if (channels == 2) {
120  if (!(esc->data[1] = av_malloc(chan_size))) {
121  av_freep(&esc->data[0]);
122  return AVERROR(ENOMEM);
123  }
124  }
125  memcpy(esc->data[0], &avpkt->data[hdr_size], chan_size);
126  if (channels == 2)
127  memcpy(esc->data[1], &avpkt->data[2*hdr_size+chan_size], chan_size);
128  }
129  if (!esc->data[0]) {
130  av_log(avctx, AV_LOG_ERROR, "unexpected empty packet\n");
131  return AVERROR_INVALIDDATA;
132  }
133 
134  /* decode next piece of data from the buffer */
135  buf_size = FFMIN(MAX_FRAME_SIZE, esc->data_size - esc->data_idx);
136  if (buf_size <= 0) {
137  *got_frame_ptr = 0;
138  return avpkt->size;
139  }
140 
141  /* get output buffer */
142  frame->nb_samples = buf_size * 2;
143  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
144  return ret;
145 
146  for (ch = 0; ch < channels; ch++) {
147  delta_decode(frame->data[ch], &esc->data[ch][esc->data_idx],
148  buf_size, &esc->fib_acc[ch], esc->table);
149  }
150 
151  esc->data_idx += buf_size;
152 
153  *got_frame_ptr = 1;
154 
155  return ((avctx->frame_num == 0) * hdr_size + buf_size) * channels;
156 }
157 
159 {
160  EightSvxContext *esc = avctx->priv_data;
161 
162  if (avctx->ch_layout.nb_channels < 1 || avctx->ch_layout.nb_channels > 2) {
163  av_log(avctx, AV_LOG_ERROR, "8SVX does not support more than 2 channels\n");
164  return AVERROR_INVALIDDATA;
165  }
166 
167  switch (avctx->codec->id) {
168  case AV_CODEC_ID_8SVX_FIB: esc->table = fibonacci; break;
169  case AV_CODEC_ID_8SVX_EXP: esc->table = exponential; break;
170  default:
171  av_assert1(0);
172  }
173  avctx->sample_fmt = AV_SAMPLE_FMT_U8P;
174 
175  return 0;
176 }
177 
179 {
180  EightSvxContext *esc = avctx->priv_data;
181 
182  av_freep(&esc->data[0]);
183  av_freep(&esc->data[1]);
184  esc->data_size = 0;
185  esc->data_idx = 0;
186 
187  return 0;
188 }
189 
190 #if CONFIG_EIGHTSVX_FIB_DECODER
192  .p.name = "8svx_fib",
193  CODEC_LONG_NAME("8SVX fibonacci"),
194  .p.type = AVMEDIA_TYPE_AUDIO,
195  .p.id = AV_CODEC_ID_8SVX_FIB,
196  .priv_data_size = sizeof (EightSvxContext),
199  .close = eightsvx_decode_close,
200  .p.capabilities = AV_CODEC_CAP_DR1,
201  .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
203 };
204 #endif
205 #if CONFIG_EIGHTSVX_EXP_DECODER
207  .p.name = "8svx_exp",
208  CODEC_LONG_NAME("8SVX exponential"),
209  .p.type = AVMEDIA_TYPE_AUDIO,
210  .p.id = AV_CODEC_ID_8SVX_EXP,
211  .priv_data_size = sizeof (EightSvxContext),
214  .close = eightsvx_decode_close,
215  .p.capabilities = AV_CODEC_CAP_DR1,
216  .p.sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_U8P,
218 };
219 #endif
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
AV_CODEC_ID_8SVX_EXP
@ AV_CODEC_ID_8SVX_EXP
Definition: codec_id.h:494
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:374
AVPacket::data
uint8_t * data
Definition: packet.h:520
table
static const uint16_t table[]
Definition: prosumer.c:203
FFCodec
Definition: codec_internal.h:126
exponential
static const int8_t exponential[16]
Definition: 8svx.c:62
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:321
MAX_FRAME_SIZE
#define MAX_FRAME_SIZE
Definition: 8svx.c:64
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:30
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:130
AVCodecContext::codec
const struct AVCodec * codec
Definition: avcodec.h:454
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:1065
eightsvx_decode_init
static av_cold int eightsvx_decode_init(AVCodecContext *avctx)
Definition: 8svx.c:158
val
static double val(void *priv, double ch)
Definition: aeval.c:78
ff_eightsvx_exp_decoder
const FFCodec ff_eightsvx_exp_decoder
AV_CODEC_ID_8SVX_FIB
@ AV_CODEC_ID_8SVX_FIB
Definition: codec_id.h:495
avassert.h
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
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:286
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
EightSvxContext
decoder context
Definition: 8svx.c:50
channels
channels
Definition: aptx.h:31
decode.h
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:271
ff_eightsvx_fib_decoder
const FFCodec ff_eightsvx_fib_decoder
EightSvxContext::data_idx
int data_idx
Definition: 8svx.c:58
EightSvxContext::table
const int8_t * table
Definition: 8svx.c:52
state
static struct @435 state
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1575
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:366
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:521
AV_SAMPLE_FMT_U8P
@ AV_SAMPLE_FMT_U8P
unsigned 8 bits, planar
Definition: samplefmt.h:63
codec_internal.h
EightSvxContext::fib_acc
uint8_t fib_acc[2]
Definition: 8svx.c:51
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1057
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
eightsvx_decode_close
static av_cold int eightsvx_decode_close(AVCodecContext *avctx)
Definition: 8svx.c:178
AVCodec::id
enum AVCodecID id
Definition: codec.h:201
delta_decode
static void delta_decode(uint8_t *dst, const uint8_t *src, int src_size, uint8_t *state, const int8_t *table)
Delta decode the compressed values in src, and put the resulting decoded samples in dst.
Definition: 8svx.c:73
common.h
av_assert1
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:56
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
fibonacci
static const int8_t fibonacci[16]
Definition: 8svx.c:61
avcodec.h
AVCodecContext::frame_num
int64_t frame_num
Frame counter, set by libavcodec.
Definition: avcodec.h:2031
ret
ret
Definition: filter_design.txt:187
eightsvx_decode_frame
static int eightsvx_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)
decode a frame
Definition: 8svx.c:90
frame
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
Definition: filter_design.txt:264
EightSvxContext::data_size
int data_size
Definition: 8svx.c:57
AVCodecContext
main external API structure.
Definition: avcodec.h:445
EightSvxContext::data
uint8_t * data[2]
Definition: 8svx.c:56
av_clip_uint8
#define av_clip_uint8
Definition: common.h:106
mem.h
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
AVPacket
This structure stores compressed data.
Definition: packet.h:497
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
src
INIT_CLIP pixel * src
Definition: h264pred_template.c:418
d
d
Definition: ffmpeg_filter.c:424
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