FFmpeg
ffmetadec.c
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1 /*
2  * Metadata demuxer
3  * Copyright (c) 2010 Anton Khirnov
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 "libavutil/bprint.h"
23 #include "libavutil/mathematics.h"
24 #include "avformat.h"
25 #include "ffmeta.h"
26 #include "internal.h"
27 #include "libavutil/dict.h"
28 
29 static int probe(const AVProbeData *p)
30 {
31  if(!memcmp(p->buf, ID_STRING, strlen(ID_STRING)))
32  return AVPROBE_SCORE_MAX;
33  return 0;
34 }
35 
36 static int64_t read_line_to_bprint_escaped(AVIOContext *s, AVBPrint *bp)
37 {
38  int len, end;
39  int64_t read = 0;
40  char tmp[1024];
41  char c;
42  char prev = ' ';
43 
44  do {
45  len = 0;
46  do {
47  c = avio_r8(s);
48  end = prev != '\\' && (c == '\r' || c == '\n' || c == '\0');
49  if (!end)
50  tmp[len++] = c;
51  prev = c;
52  } while (!end && len < sizeof(tmp));
53  av_bprint_append_data(bp, tmp, len);
54  read += len;
55  } while (!end);
56 
57  if (c == '\r' && avio_r8(s) != '\n' && !avio_feof(s))
58  avio_skip(s, -1);
59 
60  if (!c && s->error)
61  return s->error;
62 
63  if (!c && !read && avio_feof(s))
64  return AVERROR_EOF;
65 
66  return read;
67 }
68 
69 static void get_bprint_line(AVIOContext *s, AVBPrint *bp)
70 {
71 
72  do {
73  av_bprint_clear(bp);
75  } while (!avio_feof(s) && (bp->str[0] == ';' || bp->str[0] == '#' || bp->str[0] == 0));
76 }
77 
78 static void get_line(AVIOContext *s, uint8_t *buf, int size)
79 {
80  do {
81  uint8_t c;
82  int i = 0;
83 
84  while ((c = avio_r8(s))) {
85  if (c == '\\') {
86  if (i < size - 1)
87  buf[i++] = c;
88  c = avio_r8(s);
89  } else if (c == '\n')
90  break;
91 
92  if (i < size - 1)
93  buf[i++] = c;
94  }
95  buf[i] = 0;
96  } while (!avio_feof(s) && (buf[0] == ';' || buf[0] == '#' || buf[0] == 0));
97 }
98 
100 {
101  uint8_t line[256];
102  int64_t start, end;
103  AVRational tb = {1, 1e9};
104 
105  get_line(s->pb, line, sizeof(line));
106 
107  if (sscanf(line, "TIMEBASE=%d/%d", &tb.num, &tb.den))
108  get_line(s->pb, line, sizeof(line));
109  if (!sscanf(line, "START=%"SCNd64, &start)) {
110  av_log(s, AV_LOG_ERROR, "Expected chapter start timestamp, found %s.\n", line);
111  start = (s->nb_chapters && s->chapters[s->nb_chapters - 1]->end != AV_NOPTS_VALUE) ?
112  s->chapters[s->nb_chapters - 1]->end : 0;
113  } else
114  get_line(s->pb, line, sizeof(line));
115 
116  if (!sscanf(line, "END=%"SCNd64, &end)) {
117  av_log(s, AV_LOG_ERROR, "Expected chapter end timestamp, found %s.\n", line);
118  end = AV_NOPTS_VALUE;
119  }
120 
121  return avpriv_new_chapter(s, s->nb_chapters, tb, start, end, NULL);
122 }
123 
124 static uint8_t *unescape(const uint8_t *buf, int size)
125 {
126  uint8_t *ret = av_malloc(size + 1);
127  uint8_t *p1 = ret;
128  const uint8_t *p2 = buf;
129 
130  if (!ret)
131  return NULL;
132 
133  while (p2 < buf + size) {
134  if (*p2 == '\\')
135  p2++;
136  *p1++ = *p2++;
137  }
138  *p1 = 0;
139  return ret;
140 }
141 
142 static int read_tag(const uint8_t *line, AVDictionary **m)
143 {
144  uint8_t *key, *value;
145  const uint8_t *p = line;
146 
147  /* find first not escaped '=' */
148  while (1) {
149  if (*p == '=')
150  break;
151  else if (*p == '\\')
152  p++;
153 
154  if (*p++)
155  continue;
156 
157  return 0;
158  }
159 
160  if (!(key = unescape(line, p - line)))
161  return AVERROR(ENOMEM);
162  if (!(value = unescape(p + 1, strlen(p + 1)))) {
163  av_free(key);
164  return AVERROR(ENOMEM);
165  }
166 
168  return 0;
169 }
170 
172 {
173  AVDictionary **m = &s->metadata;
174  AVBPrint bp;
175 
177 
178  while(!avio_feof(s->pb)) {
179  get_bprint_line(s->pb, &bp);
180 
181  if (!memcmp(bp.str, ID_STREAM, strlen(ID_STREAM))) {
183 
184  if (!st)
185  return AVERROR(ENOMEM);
186 
189 
190  m = &st->metadata;
191  } else if (!memcmp(bp.str, ID_CHAPTER, strlen(ID_CHAPTER))) {
192  AVChapter *ch = read_chapter(s);
193 
194  if (!ch)
195  return AVERROR(ENOMEM);
196 
197  m = &ch->metadata;
198  } else
199  read_tag(bp.str, m);
200  }
201 
202  av_bprint_finalize(&bp, NULL);
203 
204  s->start_time = 0;
205  if (s->nb_chapters)
206  s->duration = av_rescale_q(s->chapters[s->nb_chapters - 1]->end,
207  s->chapters[s->nb_chapters - 1]->time_base,
209 
210  return 0;
211 }
212 
214 {
215  return AVERROR_EOF;
216 }
217 
219  .name = "ffmetadata",
220  .long_name = NULL_IF_CONFIG_SMALL("FFmpeg metadata in text"),
221  .read_probe = probe,
222  .read_header = read_header,
223  .read_packet = read_packet,
224 };
unsigned int nb_chapters
Number of chapters in AVChapter array.
Definition: avformat.h:1587
static void get_line(AVIOContext *s, uint8_t *buf, int size)
Definition: ffmetadec.c:78
#define ID_CHAPTER
Definition: ffmeta.h:26
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
static int read_header(AVFormatContext *s)
Definition: ffmetadec.c:171
Dummy codec for streams containing only metadata information.
Definition: avcodec.h:710
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: ffmetadec.c:213
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3968
int num
Numerator.
Definition: rational.h:59
static int probe(const AVProbeData *p)
Definition: ffmetadec.c:29
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:334
const char * key
static AVPacket pkt
AVDictionary * metadata
Definition: avformat.h:1319
int av_bprint_finalize(AVBPrint *buf, char **ret_str)
Finalize a print buffer.
Definition: bprint.c:235
static int read_tag(const uint8_t *line, AVDictionary **m)
Definition: ffmetadec.c:142
#define AV_DICT_DONT_STRDUP_KEY
Take ownership of a key that&#39;s been allocated with av_malloc() or another memory allocation function...
Definition: dict.h:73
AVChapter * avpriv_new_chapter(AVFormatContext *s, int id, AVRational time_base, int64_t start, int64_t end, const char *title)
Add a new chapter.
Definition: utils.c:4630
Format I/O context.
Definition: avformat.h:1358
Public dictionary API.
static uint8_t * unescape(const uint8_t *buf, int size)
Definition: ffmetadec.c:124
uint8_t
#define av_malloc(s)
Opaque data information usually continuous.
Definition: avutil.h:203
#define ID_STRING
Definition: ffmeta.h:25
static void get_bprint_line(AVIOContext *s, AVBPrint *bp)
Definition: ffmetadec.c:69
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
GLsizei GLboolean const GLfloat * value
Definition: opengl_enc.c:108
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4502
void av_bprint_append_data(AVBPrint *buf, const char *data, unsigned size)
Append data to a print buffer.
Definition: bprint.c:158
#define AVERROR_EOF
End of file.
Definition: error.h:55
ptrdiff_t size
Definition: opengl_enc.c:100
#define av_log(a,...)
int64_t av_rescale_q(int64_t a, AVRational bq, AVRational cq)
Rescale a 64-bit integer by 2 rational numbers.
Definition: mathematics.c:142
#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
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1598
#define AV_BPRINT_SIZE_UNLIMITED
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
void av_bprint_init(AVBPrint *buf, unsigned size_init, unsigned size_max)
Definition: bprint.c:69
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3964
AVChapter ** chapters
Definition: avformat.h:1588
Definition: graph2dot.c:48
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:641
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:448
#define AV_DICT_DONT_STRDUP_VAL
Take ownership of a value that&#39;s been allocated with av_malloc() or another memory allocation functio...
Definition: dict.h:76
#define ID_STREAM
Definition: ffmeta.h:27
#define s(width, name)
Definition: cbs_vp9.c:257
AVDictionary * metadata
Definition: avformat.h:945
Stream structure.
Definition: avformat.h:881
int64_t end
chapter start/end time in time_base units
Definition: avformat.h:1318
#define AV_TIME_BASE_Q
Internal time base represented as fractional value.
Definition: avutil.h:260
AVIOContext * pb
I/O context.
Definition: avformat.h:1400
void * buf
Definition: avisynth_c.h:766
AVInputFormat ff_ffmetadata_demuxer
Definition: ffmetadec.c:218
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
static int64_t read_line_to_bprint_escaped(AVIOContext *s, AVBPrint *bp)
Definition: ffmetadec.c:36
Rational number (pair of numerator and denominator).
Definition: rational.h:58
int error
contains the error code or 0 if no error happened
Definition: avio.h:245
This structure contains the data a format has to probe a file.
Definition: avformat.h:446
uint8_t pi<< 24) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_U8,(uint64_t)((*(const uint8_t *) pi-0x80U))<< 56) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_U8,(*(const uint8_t *) pi-0x80)*(1.0f/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_U8,(*(const uint8_t *) pi-0x80)*(1.0/(1<< 7))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S16,(*(const int16_t *) pi >>8)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S16,(uint64_t)(*(const int16_t *) pi)<< 48) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S16,*(const int16_t *) pi *(1.0f/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S16,*(const int16_t *) pi *(1.0/(1<< 15))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S32,(*(const int32_t *) pi >>24)+0x80) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_S32,(uint64_t)(*(const int32_t *) pi)<< 32) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S32,*(const int32_t *) pi *(1.0f/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S32,*(const int32_t *) pi *(1.0/(1U<< 31))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_S64,(*(const int64_t *) pi >>56)+0x80) CONV_FUNC(AV_SAMPLE_FMT_FLT, float, AV_SAMPLE_FMT_S64,*(const int64_t *) pi *(1.0f/(UINT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_DBL, double, AV_SAMPLE_FMT_S64,*(const int64_t *) pi *(1.0/(UINT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_FLT, av_clip_uint8(lrintf(*(const float *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_FLT, av_clip_int16(lrintf(*(const float *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_FLT, av_clipl_int32(llrintf(*(const float *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_FLT, llrintf(*(const float *) pi *(UINT64_C(1)<< 63))) CONV_FUNC(AV_SAMPLE_FMT_U8, uint8_t, AV_SAMPLE_FMT_DBL, av_clip_uint8(lrint(*(const double *) pi *(1<< 7))+0x80)) CONV_FUNC(AV_SAMPLE_FMT_S16, int16_t, AV_SAMPLE_FMT_DBL, av_clip_int16(lrint(*(const double *) pi *(1<< 15)))) CONV_FUNC(AV_SAMPLE_FMT_S32, int32_t, AV_SAMPLE_FMT_DBL, av_clipl_int32(llrint(*(const double *) pi *(1U<< 31)))) CONV_FUNC(AV_SAMPLE_FMT_S64, int64_t, AV_SAMPLE_FMT_DBL, llrint(*(const double *) pi *(UINT64_C(1)<< 63)))#define FMT_PAIR_FUNC(out, in) static conv_func_type *const fmt_pair_to_conv_functions[AV_SAMPLE_FMT_NB *AV_SAMPLE_FMT_NB]={FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_U8), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S16), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S32), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_FLT), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_DBL), FMT_PAIR_FUNC(AV_SAMPLE_FMT_U8, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S16, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S32, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_FLT, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_DBL, AV_SAMPLE_FMT_S64), FMT_PAIR_FUNC(AV_SAMPLE_FMT_S64, AV_SAMPLE_FMT_S64),};static void cpy1(uint8_t **dst, const uint8_t **src, int len){memcpy(*dst,*src, len);}static void cpy2(uint8_t **dst, const uint8_t **src, int len){memcpy(*dst,*src, 2 *len);}static void cpy4(uint8_t **dst, const uint8_t **src, int len){memcpy(*dst,*src, 4 *len);}static void cpy8(uint8_t **dst, const uint8_t **src, int len){memcpy(*dst,*src, 8 *len);}AudioConvert *swri_audio_convert_alloc(enum AVSampleFormat out_fmt, enum AVSampleFormat in_fmt, int channels, const int *ch_map, int flags){AudioConvert *ctx;conv_func_type *f=fmt_pair_to_conv_functions[av_get_packed_sample_fmt(out_fmt)+AV_SAMPLE_FMT_NB *av_get_packed_sample_fmt(in_fmt)];if(!f) return NULL;ctx=av_mallocz(sizeof(*ctx));if(!ctx) return NULL;if(channels==1){in_fmt=av_get_planar_sample_fmt(in_fmt);out_fmt=av_get_planar_sample_fmt(out_fmt);}ctx->channels=channels;ctx->conv_f=f;ctx->ch_map=ch_map;if(in_fmt==AV_SAMPLE_FMT_U8||in_fmt==AV_SAMPLE_FMT_U8P) memset(ctx->silence, 0x80, sizeof(ctx->silence));if(out_fmt==in_fmt &&!ch_map){switch(av_get_bytes_per_sample(in_fmt)){case 1:ctx->simd_f=cpy1;break;case 2:ctx->simd_f=cpy2;break;case 4:ctx->simd_f=cpy4;break;case 8:ctx->simd_f=cpy8;break;}}if(HAVE_X86ASM &&1) swri_audio_convert_init_x86(ctx, out_fmt, in_fmt, channels);if(ARCH_ARM) swri_audio_convert_init_arm(ctx, out_fmt, in_fmt, channels);if(ARCH_AARCH64) swri_audio_convert_init_aarch64(ctx, out_fmt, in_fmt, channels);return ctx;}void swri_audio_convert_free(AudioConvert **ctx){av_freep(ctx);}int swri_audio_convert(AudioConvert *ctx, AudioData *out, AudioData *in, int len){int ch;int off=0;const int os=(out->planar?1:out->ch_count)*out->bps;unsigned misaligned=0;av_assert0(ctx->channels==out->ch_count);if(ctx->in_simd_align_mask){int planes=in->planar?in->ch_count:1;unsigned m=0;for(ch=0;ch< planes;ch++) m|=(intptr_t) in->ch[ch];misaligned|=m &ctx->in_simd_align_mask;}if(ctx->out_simd_align_mask){int planes=out->planar?out->ch_count:1;unsigned m=0;for(ch=0;ch< planes;ch++) m|=(intptr_t) out->ch[ch];misaligned|=m &ctx->out_simd_align_mask;}if(ctx->simd_f &&!ctx->ch_map &&!misaligned){off=len &~15;av_assert1(off >=0);av_assert1(off<=len);av_assert2(ctx->channels==SWR_CH_MAX||!in->ch[ctx->channels]);if(off >0){if(out->planar==in->planar){int planes=out->planar?out->ch_count:1;for(ch=0;ch< planes;ch++){ctx->simd_f(out-> ch ch
Definition: audioconvert.c:56
int64_t start_time
Position of the first frame of the component, in AV_TIME_BASE fractional seconds. ...
Definition: avformat.h:1463
void av_bprint_clear(AVBPrint *buf)
Reset the string to "" but keep internal allocated data.
Definition: bprint.c:227
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:458
Main libavformat public API header.
The official guide to swscale for confused that consecutive non overlapping rectangles of slice_bottom special converter These generally are unscaled converters of common like for each output line the vertical scaler pulls lines from a ring buffer When the ring buffer does not contain the wanted line
Definition: swscale.txt:33
static AVChapter * read_chapter(AVFormatContext *s)
Definition: ffmetadec.c:99
AVRational time_base
time base in which the start/end timestamps are specified
Definition: avformat.h:1317
int den
Denominator.
Definition: rational.h:60
#define av_free(p)
int len
int64_t duration
Duration of the stream, in AV_TIME_BASE fractional seconds.
Definition: avformat.h:1473
void INT64 start
Definition: avisynth_c.h:766
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1028
int avio_feof(AVIOContext *s)
Similar to feof() but also returns nonzero on read errors.
Definition: aviobuf.c:361
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
This structure stores compressed data.
Definition: avcodec.h:1457
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
#define tb
Definition: regdef.h:68
static uint8_t tmp[11]
Definition: aes_ctr.c:26