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webpenc.c
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1 /*
2  * webp muxer
3  * Copyright (c) 2014 Michael Niedermayer
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/intreadwrite.h"
23 #include "libavutil/opt.h"
24 #include "avformat.h"
25 #include "internal.h"
26 
27 typedef struct WebpContext{
28  AVClass *class;
31  int loop;
34 } WebpContext;
35 
37 {
38  AVStream *st;
39 
40  if (s->nb_streams != 1) {
41  av_log(s, AV_LOG_ERROR, "Only exactly 1 stream is supported\n");
42  return AVERROR(EINVAL);
43  }
44  st = s->streams[0];
45  if (st->codecpar->codec_id != AV_CODEC_ID_WEBP) {
46  av_log(s, AV_LOG_ERROR, "Only WebP is supported\n");
47  return AVERROR(EINVAL);
48  }
49  avpriv_set_pts_info(st, 24, 1, 1000);
50 
51  return 0;
52 }
53 
55 {
56  if (pkt->size) {
57  int skip = 0;
58  unsigned flags = 0;
59 
60  if (pkt->size < 4)
61  return 0;
62  if (AV_RL32(pkt->data) == AV_RL32("RIFF"))
63  skip = 12;
64 
65  if (pkt->size < skip + 4)
66  return 0;
67  if (AV_RL32(pkt->data + skip) == AV_RL32("VP8X")) {
68  flags |= pkt->data[skip + 4 + 4];
69  }
70 
71  if (flags & 2) // ANIMATION_FLAG is on
72  return 1;
73  }
74  return 0;
75 }
76 
77 static int flush(AVFormatContext *s, int trailer, int64_t pts)
78 {
79  WebpContext *w = s->priv_data;
80  AVStream *st = s->streams[0];
81 
82  if (w->last_pkt.size) {
83  int skip = 0;
84  unsigned flags = 0;
85  int vp8x = 0;
86 
87  if (w->last_pkt.size < 4)
88  return 0;
89  if (AV_RL32(w->last_pkt.data) == AV_RL32("RIFF"))
90  skip = 12;
91 
92  if (w->last_pkt.size < skip + 4)
93  return 0; // Safe to do this as a valid WebP bitstream is >=30 bytes.
94  if (AV_RL32(w->last_pkt.data + skip) == AV_RL32("VP8X")) {
95  flags |= w->last_pkt.data[skip + 4 + 4];
96  vp8x = 1;
97  skip += AV_RL32(w->last_pkt.data + skip + 4) + 8;
98  }
99 
100  if (!w->wrote_webp_header) {
101  avio_write(s->pb, "RIFF\0\0\0\0WEBP", 12);
102  w->wrote_webp_header = 1;
103  if (w->frame_count > 1) // first non-empty packet
104  w->frame_count = 1; // so we don't count previous empty packets.
105  }
106 
107  if (w->frame_count == 1) {
108  if (!trailer) {
109  vp8x = 1;
110  flags |= 2 + 16;
111  }
112 
113  if (vp8x) {
114  avio_write(s->pb, "VP8X", 4);
115  avio_wl32(s->pb, 10);
116  avio_w8(s->pb, flags);
117  avio_wl24(s->pb, 0);
118  avio_wl24(s->pb, st->codecpar->width - 1);
119  avio_wl24(s->pb, st->codecpar->height - 1);
120  }
121  if (!trailer) {
122  avio_write(s->pb, "ANIM", 4);
123  avio_wl32(s->pb, 6);
124  avio_wl32(s->pb, 0xFFFFFFFF);
125  avio_wl16(s->pb, w->loop);
126  }
127  }
128 
129  if (w->frame_count > trailer) {
130  avio_write(s->pb, "ANMF", 4);
131  avio_wl32(s->pb, 16 + w->last_pkt.size - skip);
132  avio_wl24(s->pb, 0);
133  avio_wl24(s->pb, 0);
134  avio_wl24(s->pb, st->codecpar->width - 1);
135  avio_wl24(s->pb, st->codecpar->height - 1);
136  if (w->last_pkt.pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE) {
137  avio_wl24(s->pb, pts - w->last_pkt.pts);
138  } else
139  avio_wl24(s->pb, w->last_pkt.duration);
140  avio_w8(s->pb, 0);
141  }
142  avio_write(s->pb, w->last_pkt.data + skip, w->last_pkt.size - skip);
144  }
145 
146  return 0;
147 }
148 
150 {
151  WebpContext *w = s->priv_data;
153 
154  if (w->using_webp_anim_encoder) {
155  avio_write(s->pb, pkt->data, pkt->size);
156  w->wrote_webp_header = 1; // for good measure
157  } else {
158  int ret;
159  if ((ret = flush(s, 0, pkt->pts)) < 0)
160  return ret;
161  av_copy_packet(&w->last_pkt, pkt);
162  }
163  ++w->frame_count;
164 
165  return 0;
166 }
167 
169 {
170  unsigned filesize;
171  WebpContext *w = s->priv_data;
172 
173  if (w->using_webp_anim_encoder) {
174  if ((w->frame_count > 1) && w->loop) { // Write loop count.
175  avio_seek(s->pb, 42, SEEK_SET);
176  avio_wl16(s->pb, w->loop);
177  }
178  } else {
179  int ret;
180  if ((ret = flush(s, 1, AV_NOPTS_VALUE)) < 0)
181  return ret;
182 
183  filesize = avio_tell(s->pb);
184  avio_seek(s->pb, 4, SEEK_SET);
185  avio_wl32(s->pb, filesize - 8);
186  // Note: without the following, avio only writes 8 bytes to the file.
187  avio_seek(s->pb, filesize, SEEK_SET);
188  }
189 
190  return 0;
191 }
192 
193 #define OFFSET(x) offsetof(WebpContext, x)
194 #define ENC AV_OPT_FLAG_ENCODING_PARAM
195 static const AVOption options[] = {
196  { "loop", "Number of times to loop the output: 0 - infinite loop", OFFSET(loop),
197  AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 65535, ENC },
198  { NULL },
199 };
200 
201 static const AVClass webp_muxer_class = {
202  .class_name = "WebP muxer",
203  .item_name = av_default_item_name,
204  .version = LIBAVUTIL_VERSION_INT,
205  .option = options,
206 };
208  .name = "webp",
209  .long_name = NULL_IF_CONFIG_SMALL("WebP"),
210  .extensions = "webp",
211  .priv_data_size = sizeof(WebpContext),
212  .video_codec = AV_CODEC_ID_WEBP,
216  .priv_class = &webp_muxer_class,
218 };
#define NULL
Definition: coverity.c:32
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:446
const char * s
Definition: avisynth_c.h:768
AVOption.
Definition: opt.h:245
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
AVPacket last_pkt
Definition: webpenc.c:30
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4560
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3980
int size
Definition: avcodec.h:1602
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:230
static AVPacket pkt
int loop
Definition: webpenc.c:31
Format I/O context.
Definition: avformat.h:1338
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:72
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:346
int width
Video only.
Definition: avcodec.h:4046
AVOptions.
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: avcodec.h:1619
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1406
uint8_t * data
Definition: avcodec.h:1601
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:511
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:204
#define av_log(a,...)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
static const AVOption options[]
Definition: webpenc.c:195
av_default_item_name
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
int using_webp_anim_encoder
Definition: webpenc.c:33
unsigned int nb_streams
Number of elements in AVFormatContext.streams.
Definition: avformat.h:1394
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:94
const char * name
Definition: avformat.h:524
static int webp_write_header(AVFormatContext *s)
Definition: webpenc.c:36
int wrote_webp_header
Definition: webpenc.c:32
static int is_animated_webp_packet(AVPacket *pkt)
Definition: webpenc.c:54
int frame_count
Definition: webpenc.c:29
static const AVClass webp_muxer_class
Definition: webpenc.c:201
Stream structure.
Definition: avformat.h:889
AVIOContext * pb
I/O context.
Definition: avformat.h:1380
static int loop
Definition: ffplay.c:335
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:182
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:567
int av_copy_packet(AVPacket *dst, const AVPacket *src)
Copy packet, including contents.
Definition: avpacket.c:264
static void write_packet(OutputFile *of, AVPacket *pkt, OutputStream *ost)
Definition: ffmpeg.c:645
Describe the class of an AVClass context structure.
Definition: log.h:67
void avio_wl24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:458
static int flush(AVFormatContext *s, int trailer, int64_t pts)
Definition: webpenc.c:77
static int64_t pts
Global timestamp for the audio frames.
static int flags
Definition: cpu.c:47
static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: webpenc.c:149
AVOutputFormat ff_webp_muxer
Definition: webpenc.c:207
Main libavformat public API header.
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:489
void * priv_data
Format private data.
Definition: avformat.h:1366
#define OFFSET(x)
Definition: webpenc.c:193
static void write_header(FFV1Context *f)
Definition: ffv1enc.c:344
AVCodecParameters * codecpar
Definition: avformat.h:1241
static int webp_write_trailer(AVFormatContext *s)
Definition: webpenc.c:168
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:87
This structure stores compressed data.
Definition: avcodec.h:1578
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1594
#define ENC
Definition: webpenc.c:194
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:242