FFmpeg
s302m.c
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1 /*
2  * SMPTE 302M decoder
3  * Copyright (c) 2008 Laurent Aimar <fenrir@videolan.org>
4  * Copyright (c) 2009 Baptiste Coudurier <baptiste.coudurier@gmail.com>
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/opt.h"
26 #include "libavutil/log.h"
27 #include "libavutil/reverse.h"
28 #include "avcodec.h"
29 #include "codec_internal.h"
30 #include "internal.h"
31 #include "mathops.h"
32 
33 #define AES3_HEADER_LEN 4
34 
35 typedef struct S302Context {
36  AVClass *class;
38 } S302Context;
39 
40 static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf,
41  int buf_size)
42 {
43  uint32_t h;
44  int frame_size, channels, bits;
45 
46  if (buf_size <= AES3_HEADER_LEN) {
47  av_log(avctx, AV_LOG_ERROR, "frame is too short\n");
48  return AVERROR_INVALIDDATA;
49  }
50 
51  /*
52  * AES3 header :
53  * size: 16
54  * number channels 2
55  * channel_id 8
56  * bits per samples 2
57  * alignments 4
58  */
59 
60  h = AV_RB32(buf);
61  frame_size = (h >> 16) & 0xffff;
62  channels = ((h >> 14) & 0x0003) * 2 + 2;
63  bits = ((h >> 4) & 0x0003) * 4 + 16;
64 
65  if (AES3_HEADER_LEN + frame_size != buf_size || bits > 24) {
66  av_log(avctx, AV_LOG_ERROR, "frame has invalid header\n");
67  return AVERROR_INVALIDDATA;
68  }
69 
70  /* Set output properties */
71  avctx->bits_per_raw_sample = bits;
72  if (bits > 16)
74  else
76 
78  switch(channels) {
79  case 2:
81  break;
82  case 4:
84  break;
85  case 6:
87  break;
88  case 8:
91  break;
92  default:
95  break;
96  }
97 
98  return frame_size;
99 }
100 
102  int *got_frame_ptr, AVPacket *avpkt)
103 {
104  S302Context *s = avctx->priv_data;
105  const uint8_t *buf = avpkt->data;
106  int buf_size = avpkt->size;
107  int block_size, ret, channels;
108  int i;
109  int non_pcm_data_type = -1;
110 
111  int frame_size = s302m_parse_frame_header(avctx, buf, buf_size);
112  if (frame_size < 0)
113  return frame_size;
114 
115  buf_size -= AES3_HEADER_LEN;
116  buf += AES3_HEADER_LEN;
117 
118  /* get output buffer */
119  block_size = (avctx->bits_per_raw_sample + 4) / 4;
120  channels = avctx->ch_layout.nb_channels;
121  frame->nb_samples = 2 * (buf_size / block_size) / channels;
122  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
123  return ret;
124 
125  avctx->bit_rate = 48000 * channels * (avctx->bits_per_raw_sample + 4) +
126  32 * 48000 / frame->nb_samples;
127  buf_size = (frame->nb_samples * channels / 2) * block_size;
128 
129  if (avctx->bits_per_raw_sample == 24) {
130  uint32_t *o = (uint32_t *)frame->data[0];
131  for (; buf_size > 6; buf_size -= 7) {
132  *o++ = ((unsigned)ff_reverse[buf[2]] << 24) |
133  (ff_reverse[buf[1]] << 16) |
134  (ff_reverse[buf[0]] << 8);
135  *o++ = ((unsigned)ff_reverse[buf[6] & 0xf0] << 28) |
136  (ff_reverse[buf[5]] << 20) |
137  (ff_reverse[buf[4]] << 12) |
138  (ff_reverse[buf[3] & 0x0f] << 4);
139  buf += 7;
140  }
141  o = (uint32_t *)frame->data[0];
142  if (channels == 2)
143  for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
144  if (o[i] || o[i+1] || o[i+2] || o[i+3])
145  break;
146  if (o[i+4] == 0x96F87200U && o[i+5] == 0xA54E1F00) {
147  non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
148  break;
149  }
150  }
151  } else if (avctx->bits_per_raw_sample == 20) {
152  uint32_t *o = (uint32_t *)frame->data[0];
153  for (; buf_size > 5; buf_size -= 6) {
154  *o++ = ((unsigned)ff_reverse[buf[2] & 0xf0] << 28) |
155  (ff_reverse[buf[1]] << 20) |
156  (ff_reverse[buf[0]] << 12);
157  *o++ = ((unsigned)ff_reverse[buf[5] & 0xf0] << 28) |
158  (ff_reverse[buf[4]] << 20) |
159  (ff_reverse[buf[3]] << 12);
160  buf += 6;
161  }
162  o = (uint32_t *)frame->data[0];
163  if (channels == 2)
164  for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
165  if (o[i] || o[i+1] || o[i+2] || o[i+3])
166  break;
167  if (o[i+4] == 0x6F872000U && o[i+5] == 0x54E1F000) {
168  non_pcm_data_type = (o[i+6] >> 16) & 0x1F;
169  break;
170  }
171  }
172  } else {
173  uint16_t *o = (uint16_t *)frame->data[0];
174  for (; buf_size > 4; buf_size -= 5) {
175  *o++ = (ff_reverse[buf[1]] << 8) |
176  ff_reverse[buf[0]];
177  *o++ = (ff_reverse[buf[4] & 0xf0] << 12) |
178  (ff_reverse[buf[3]] << 4) |
179  (ff_reverse[buf[2]] >> 4);
180  buf += 5;
181  }
182  o = (uint16_t *)frame->data[0];
183  if (channels == 2)
184  for (i=0; i<frame->nb_samples * 2 - 6; i+=2) {
185  if (o[i] || o[i+1] || o[i+2] || o[i+3])
186  break;
187  if (o[i+4] == 0xF872U && o[i+5] == 0x4E1F) {
188  non_pcm_data_type = (o[i+6] & 0x1F);
189  break;
190  }
191  }
192  }
193 
194  if (non_pcm_data_type != -1) {
195  if (s->non_pcm_mode == 3) {
196  av_log(avctx, AV_LOG_ERROR,
197  "S302 non PCM mode with data type %d not supported\n",
198  non_pcm_data_type);
199  return AVERROR_PATCHWELCOME;
200  }
201  if (s->non_pcm_mode & 1) {
202  return avpkt->size;
203  }
204  }
205 
206  avctx->sample_rate = 48000;
207 
208  *got_frame_ptr = 1;
209 
210  return avpkt->size;
211 }
212 
213 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_DECODING_PARAM
214 static const AVOption s302m_options[] = {
215  {"non_pcm_mode", "Chooses what to do with NON-PCM", offsetof(S302Context, non_pcm_mode), AV_OPT_TYPE_INT, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
216  {"copy" , "Pass NON-PCM through unchanged" , 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 3, FLAGS, "non_pcm_mode"},
217  {"drop" , "Drop NON-PCM" , 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 3, FLAGS, "non_pcm_mode"},
218  {"decode_copy" , "Decode if possible else passthrough", 0, AV_OPT_TYPE_CONST, {.i64 = 2}, 0, 3, FLAGS, "non_pcm_mode"},
219  {"decode_drop" , "Decode if possible else drop" , 0, AV_OPT_TYPE_CONST, {.i64 = 3}, 0, 3, FLAGS, "non_pcm_mode"},
220  {NULL}
221 };
222 
223 static const AVClass s302m_class = {
224  .class_name = "SMPTE 302M Decoder",
225  .item_name = av_default_item_name,
226  .option = s302m_options,
227  .version = LIBAVUTIL_VERSION_INT,
228 };
229 
231  .p.name = "s302m",
232  .p.long_name = NULL_IF_CONFIG_SMALL("SMPTE 302M"),
233  .p.type = AVMEDIA_TYPE_AUDIO,
234  .p.id = AV_CODEC_ID_S302M,
235  .p.priv_class = &s302m_class,
236  .priv_data_size = sizeof(S302Context),
238  .p.capabilities = AV_CODEC_CAP_CHANNEL_CONF |
240 };
opt.h
AVCodecContext::sample_rate
int sample_rate
samples per second
Definition: avcodec.h:998
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:325
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
ff_reverse
const uint8_t ff_reverse[256]
Definition: reverse.c:23
FFCodec
Definition: codec_internal.h:112
AES3_HEADER_LEN
#define AES3_HEADER_LEN
Definition: s302m.c:33
AV_CHANNEL_LAYOUT_STEREO
#define AV_CHANNEL_LAYOUT_STEREO
Definition: channel_layout.h:354
reverse.h
AVChannelLayout::order
enum AVChannelOrder order
Channel order used in this layout.
Definition: channel_layout.h:295
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:300
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:116
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2057
s302m_class
static const AVClass s302m_class
Definition: s302m.c:223
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
AV_CODEC_ID_S302M
@ AV_CODEC_ID_S302M
Definition: codec_id.h:343
FLAGS
#define FLAGS
Definition: s302m.c:213
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:254
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AV_CHANNEL_ORDER_UNSPEC
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
Definition: channel_layout.h:106
frame_size
int frame_size
Definition: mxfenc.c:2201
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AV_CH_LAYOUT_STEREO_DOWNMIX
#define AV_CH_LAYOUT_STEREO_DOWNMIX
Definition: channel_layout.h:231
bits
uint8_t bits
Definition: vp3data.h:141
AVCodecContext::bits_per_raw_sample
int bits_per_raw_sample
Bits per sample/pixel of internal libavcodec pixel/sample format.
Definition: avcodec.h:1448
channels
channels
Definition: aptx.h:32
if
if(ret)
Definition: filter_design.txt:179
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:66
NULL
#define NULL
Definition: coverity.c:32
AVERROR_PATCHWELCOME
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:64
S302Context
Definition: s302m.c:35
AVCodecContext::bit_rate
int64_t bit_rate
the average bitrate
Definition: avcodec.h:439
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
mathops.h
ff_s302m_decoder
const FFCodec ff_s302m_decoder
Definition: s302m.c:230
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:630
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:109
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1403
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:375
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:290
codec_internal.h
for
for(k=2;k<=8;++k)
Definition: h264pred_template.c:425
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1014
s302m_decode_frame
static int s302m_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)
Definition: s302m.c:101
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
S302Context::non_pcm_mode
int non_pcm_mode
Definition: s302m.c:37
AV_CH_LAYOUT_5POINT1_BACK
#define AV_CH_LAYOUT_5POINT1_BACK
Definition: channel_layout.h:217
log.h
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
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:203
avcodec.h
av_channel_layout_from_mask
FF_ENABLE_DEPRECATION_WARNINGS int av_channel_layout_from_mask(AVChannelLayout *channel_layout, uint64_t mask)
Initialize a native channel layout from a bitmask indicating which channels are present.
Definition: channel_layout.c:389
ret
ret
Definition: filter_design.txt:187
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:71
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
AVCodecContext
main external API structure.
Definition: avcodec.h:389
channel_layout.h
s302m_options
static const AVOption s302m_options[]
Definition: s302m.c:214
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:416
AVPacket
This structure stores compressed data.
Definition: packet.h:351
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
h
h
Definition: vp9dsp_template.c:2038
AV_CHANNEL_LAYOUT_QUAD
#define AV_CHANNEL_LAYOUT_QUAD
Definition: channel_layout.h:362
AV_CHANNEL_LAYOUT_5POINT1_BACK
#define AV_CHANNEL_LAYOUT_5POINT1_BACK
Definition: channel_layout.h:366
AV_SAMPLE_FMT_S32
@ AV_SAMPLE_FMT_S32
signed 32 bits
Definition: samplefmt.h:59
AV_OPT_TYPE_CONST
@ AV_OPT_TYPE_CONST
Definition: opt.h:234
s302m_parse_frame_header
static int s302m_parse_frame_header(AVCodecContext *avctx, const uint8_t *buf, int buf_size)
Definition: s302m.c:40