FFmpeg: libavformat/astenc.c Source File

FFmpeg
astenc.c
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1 /*
2  * AST muxer
3  * Copyright (c) 2012 James Almer
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 #include "avformat.h"
23 #include "avio_internal.h"
24 #include "internal.h"
25 #include "ast.h"
26 #include "mux.h"
27 #include "libavutil/mathematics.h"
28 #include "libavutil/opt.h"
29 
30  typedef struct ASTMuxContext {
31   AVClass *class;
32   int64_t size;
33   int64_t samples;
34   int64_t loopstart;
35   int64_t loopend;
36   int fbs;
37 } ASTMuxContext;
38 
39  #define CHECK_LOOP(type) \
40  if (ast->loop ## type > 0) { \
41  ast->loop ## type = av_rescale_rnd(ast->loop ## type, par->sample_rate, 1000, AV_ROUND_DOWN); \
42  if (ast->loop ## type < 0 || ast->loop ## type > UINT_MAX) { \
43  av_log(s, AV_LOG_ERROR, "Invalid loop" #type " value\n"); \
44  return AVERROR(EINVAL); \
45  } \
46  }
47 
48  static int ast_write_header(AVFormatContext *s)
49 {
50  ASTMuxContext *ast = s->priv_data;
51  AVIOContext *pb = s->pb;
52  AVCodecParameters *par;
53  unsigned int codec_tag;
54 
55  if (s->nb_streams == 1) {
56  par = s->streams[0]->codecpar;
57  } else {
58  av_log(s, AV_LOG_ERROR, "only one stream is supported\n");
59  return AVERROR(EINVAL);
60  }
61 
62  if (par->codec_id == AV_CODEC_ID_ADPCM_AFC) {
63  av_log(s, AV_LOG_ERROR, "muxing ADPCM AFC is not implemented\n");
64  return AVERROR_PATCHWELCOME;
65  }
66 
67  codec_tag = ff_codec_get_tag(ff_codec_ast_tags, par->codec_id);
68  if (!codec_tag) {
69  av_log(s, AV_LOG_ERROR, "unsupported codec\n");
70  return AVERROR(EINVAL);
71  }
72 
73  if (ast->loopend > 0 && ast->loopstart >= ast->loopend) {
74  av_log(s, AV_LOG_ERROR, "loopend can't be less or equal to loopstart\n");
75  return AVERROR(EINVAL);
76  }
77 
78  /* Convert milliseconds to samples */
79  CHECK_LOOP(start)
80  CHECK_LOOP(end)
81 
82  ffio_wfourcc(pb, "STRM");
83 
84  ast->size = avio_tell(pb);
85  avio_wb32(pb, 0); /* File size minus header */
86  avio_wb16(pb, codec_tag);
87  avio_wb16(pb, 16); /* Bit depth */
88  avio_wb16(pb, par->ch_layout.nb_channels);
89  avio_wb16(pb, 0); /* Loop flag */
90  avio_wb32(pb, par->sample_rate);
91 
92  ast->samples = avio_tell(pb);
93  avio_wb32(pb, 0); /* Number of samples */
94  avio_wb32(pb, 0); /* Loopstart */
95  avio_wb32(pb, 0); /* Loopend */
96  avio_wb32(pb, 0); /* Size of first block */
97 
98  /* Unknown */
99  avio_wb32(pb, 0);
100  avio_wl32(pb, 0x7F);
101  avio_wb64(pb, 0);
102  avio_wb64(pb, 0);
103  avio_wb32(pb, 0);
104 
105  return 0;
106 }
107 
108  static int ast_write_packet(AVFormatContext *s, AVPacket *pkt)
109 {
110  AVIOContext *pb = s->pb;
111  ASTMuxContext *ast = s->priv_data;
112  AVCodecParameters *par = s->streams[0]->codecpar;
113  int size = pkt->size / par->ch_layout.nb_channels;
114 
115  if (s->streams[0]->nb_frames == 0)
116  ast->fbs = size;
117 
118  ffio_wfourcc(pb, "BLCK");
119  avio_wb32(pb, size); /* Block size */
120 
121  /* padding */
122  ffio_fill(pb, 0, 24);
123 
124  avio_write(pb, pkt->data, pkt->size);
125 
126  return 0;
127 }
128 
129  static int ast_write_trailer(AVFormatContext *s)
130 {
131  AVIOContext *pb = s->pb;
132  ASTMuxContext *ast = s->priv_data;
133  AVCodecParameters *par = s->streams[0]->codecpar;
134  int64_t file_size = avio_tell(pb);
135  int64_t samples = (file_size - 64 - (32 * s->streams[0]->nb_frames)) / par->block_align; /* PCM_S16BE_PLANAR */
136 
137  av_log(s, AV_LOG_DEBUG, "total samples: %"PRId64"\n", samples);
138 
139  if (s->pb->seekable & AVIO_SEEKABLE_NORMAL) {
140  /* Number of samples */
141  avio_seek(pb, ast->samples, SEEK_SET);
142  avio_wb32(pb, samples);
143 
144  /* Loopstart if provided */
145  if (ast->loopstart > 0) {
146  if (ast->loopstart >= samples) {
147  av_log(s, AV_LOG_WARNING, "Loopstart value is out of range and will be ignored\n");
148  ast->loopstart = -1;
149  avio_skip(pb, 4);
150  } else
151  avio_wb32(pb, ast->loopstart);
152  } else
153  avio_skip(pb, 4);
154 
155  /* Loopend if provided. Otherwise number of samples again */
156  if (ast->loopend && ast->loopstart >= 0) {
157  if (ast->loopend > samples) {
158  av_log(s, AV_LOG_WARNING, "Loopend value is out of range and will be ignored\n");
159  ast->loopend = samples;
160  }
161  avio_wb32(pb, ast->loopend);
162  } else {
163  avio_wb32(pb, samples);
164  }
165 
166  /* Size of first block */
167  avio_wb32(pb, ast->fbs);
168 
169  /* File size minus header */
170  avio_seek(pb, ast->size, SEEK_SET);
171  avio_wb32(pb, file_size - 64);
172 
173  /* Loop flag */
174  if (ast->loopstart >= 0) {
175  avio_skip(pb, 6);
176  avio_wb16(pb, 0xFFFF);
177  }
178 
179  avio_seek(pb, file_size, SEEK_SET);
180  }
181  return 0;
182 }
183 
184  #define OFFSET(obj) offsetof(ASTMuxContext, obj)
185  static const AVOption options[] = {
186  { "loopstart", "Loopstart position in milliseconds.", OFFSET(loopstart), AV_OPT_TYPE_INT64, { .i64 = -1 }, -1, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
187  { "loopend", "Loopend position in milliseconds.", OFFSET(loopend), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT_MAX, AV_OPT_FLAG_ENCODING_PARAM },
188  { NULL },
189 };
190 
191  static const AVClass ast_muxer_class = {
192  .class_name = "AST muxer",
193  .item_name = av_default_item_name,
194  .option = options,
195  .version = LIBAVUTIL_VERSION_INT,
196 };
197 
198  const FFOutputFormat ff_ast_muxer = {
199  .p.name = "ast",
200  .p.long_name = NULL_IF_CONFIG_SMALL("AST (Audio Stream)"),
201  .p.extensions = "ast",
202  .priv_data_size = sizeof(ASTMuxContext),
203  .p.audio_codec = AV_CODEC_ID_PCM_S16BE_PLANAR,
204  .p.video_codec = AV_CODEC_ID_NONE,
205  .write_header = ast_write_header,
206  .write_packet = ast_write_packet,
207  .write_trailer = ast_write_trailer,
208  .p.priv_class = &ast_muxer_class,
209  .p.codec_tag = ff_ast_codec_tags_list,
210 };
OFFSET
#define OFFSET(obj)
Definition: astenc.c:184
AV_LOG_WARNING
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:186
AVOutputFormat::name
const char * name
Definition: avformat.h:508
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
opt.h
ffio_wfourcc
static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
Definition: avio_internal.h:116
ASTMuxContext::fbs
int fbs
Definition: astenc.c:36
ast_write_trailer
static int ast_write_trailer(AVFormatContext *s)
Definition: astenc.c:129
AVCodecParameters
This struct describes the properties of an encoded stream.
Definition: codec_par.h:54
ASTMuxContext::size
int64_t size
Definition: astenc.c:32
AVPacket::data
uint8_t * data
Definition: packet.h:374
AV_CODEC_ID_PCM_S16BE_PLANAR
@ AV_CODEC_ID_PCM_S16BE_PLANAR
Definition: codec_id.h:356
AVOption
AVOption.
Definition: opt.h:251
mathematics.h
AVChannelLayout::nb_channels
int nb_channels
Number of channels in this layout.
Definition: channel_layout.h:311
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:34
ast.h
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:500
pkt
AVPacket * pkt
Definition: movenc.c:59
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
ast_muxer_class
static const AVClass ast_muxer_class
Definition: astenc.c:191
s
#define s(width, name)
Definition: cbs_vp9.c:256
AV_OPT_FLAG_ENCODING_PARAM
#define AV_OPT_FLAG_ENCODING_PARAM
a generic parameter which can be set by the user for muxing or encoding
Definition: opt.h:281
AV_CODEC_ID_ADPCM_AFC
@ AV_CODEC_ID_ADPCM_AFC
Definition: codec_id.h:396
ff_codec_ast_tags
const AVCodecTag ff_codec_ast_tags[]
Definition: ast.c:26
AV_OPT_TYPE_INT64
@ AV_OPT_TYPE_INT64
Definition: opt.h:226
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
ASTMuxContext::loopstart
int64_t loopstart
Definition: astenc.c:34
options
static const AVOption options[]
Definition: astenc.c:185
AVFormatContext
Format I/O context.
Definition: avformat.h:1104
internal.h
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
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
ASTMuxContext::samples
int64_t samples
Definition: astenc.c:33
FFOutputFormat
Definition: mux.h:30
ffio_fill
void ffio_fill(AVIOContext *s, int b, int64_t count)
Definition: aviobuf.c:208
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:213
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:178
ASTMuxContext::loopend
int64_t loopend
Definition: astenc.c:35
AVIOContext
Bytestream IO Context.
Definition: avio.h:166
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:115
size
int size
Definition: twinvq_data.h:10344
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:222
avio_wb32
void avio_wb32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:386
avio_wl32
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:378
ff_ast_muxer
const FFOutputFormat ff_ast_muxer
Definition: astenc.c:198
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
avio_internal.h
AVCodecParameters::block_align
int block_align
Audio only.
Definition: codec_par.h:185
ff_ast_codec_tags_list
const AVCodecTag *const ff_ast_codec_tags_list[]
Definition: ast.c:32
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:252
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
avformat.h
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:41
ff_codec_get_tag
unsigned int ff_codec_get_tag(const AVCodecTag *tags, enum AVCodecID id)
Definition: utils.c:134
samples
Filter the word "frame" indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:339
avio_wb64
void avio_wb64(AVIOContext *s, uint64_t val)
Definition: aviobuf.c:452
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:62
AVPacket
This structure stores compressed data.
Definition: packet.h:351
avio_wb16
void avio_wb16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:464
ast_write_header
static int ast_write_header(AVFormatContext *s)
Definition: astenc.c:48
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
ast_write_packet
static int ast_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: astenc.c:108
CHECK_LOOP
#define CHECK_LOOP(type)
Definition: astenc.c:39
mux.h
ASTMuxContext
Definition: astenc.c:30
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