FFmpeg
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 "libavcodec/bytestream.h"
25 #include "avformat.h"
26 #include "internal.h"
27 #include "mux.h"
28 
29 typedef struct WebpContext{
30  AVClass *class;
32  AVPacket *last_pkt; /* Not owned by us */
33  int loop;
36 } WebpContext;
37 
39 {
40  WebpContext *const w = s->priv_data;
41  AVStream *st = s->streams[0];
42 
43  w->last_pkt = ffformatcontext(s)->pkt;
44 
45  avpriv_set_pts_info(st, 24, 1, 1000);
46 
47  return 0;
48 }
49 
51 {
52  int skip = 0;
53  unsigned flags = 0;
54 
55  if (pkt->size < 4)
56  return AVERROR_INVALIDDATA;
57  if (AV_RL32(pkt->data) == AV_RL32("RIFF"))
58  skip = 12;
59  // Safe to do this as a valid WebP bitstream is >=30 bytes.
60  if (pkt->size < skip + 4)
61  return AVERROR_INVALIDDATA;
62  if (AV_RL32(pkt->data + skip) == AV_RL32("VP8X")) {
63  flags |= pkt->data[skip + 4 + 4];
64  }
65 
66  if (flags & 2) // ANIMATION_FLAG is on
67  return 1;
68  return 0;
69 }
70 
71 /**
72  * Returns 1 if it has written a RIFF header with a correct length field
73  */
74 static int flush(AVFormatContext *s, int trailer, int64_t pts)
75 {
76  WebpContext *w = s->priv_data;
77  AVStream *st = s->streams[0];
78  uint8_t buf[12 /* RIFF+WEBP */ + 18 /* VP8X */ +
79  14 /* ANIM */ + 24 /* ANMF */], *bufp = buf;
80  int writing_webp_header = 0, skip = 0;
81  unsigned flags = 0;
82  int vp8x = 0;
83 
84  if (!w->last_pkt->size)
85  return 0;
86 
87  if (AV_RL32(w->last_pkt->data) == AV_RL32("RIFF"))
88  skip = 12;
89 
90  if (AV_RL32(w->last_pkt->data + skip) == AV_RL32("VP8X")) {
91  flags |= w->last_pkt->data[skip + 4 + 4];
92  vp8x = 1;
93  skip += AV_RL32(w->last_pkt->data + skip + 4) + 8;
94  }
95 
96  if (!w->wrote_webp_header) {
97  bytestream_put_le32(&bufp, MKTAG('R', 'I', 'F', 'F'));
98  bytestream_put_le32(&bufp, 0); /* Size to be patched later */
99  bytestream_put_le32(&bufp, MKTAG('W', 'E', 'B', 'P'));
100  writing_webp_header = 1;
101  w->wrote_webp_header = 1;
102  if (w->frame_count > 1) // first non-empty packet
103  w->frame_count = 1; // so we don't count previous empty packets.
104  }
105 
106  if (w->frame_count == 1) {
107  if (!trailer) {
108  vp8x = 1;
109  flags |= 2 + 16;
110  }
111 
112  if (vp8x) {
113  bytestream_put_le32(&bufp, MKTAG('V', 'P', '8', 'X'));
114  bytestream_put_le32(&bufp, 10);
115  bytestream_put_byte(&bufp, flags);
116  bytestream_put_le24(&bufp, 0);
117  bytestream_put_le24(&bufp, st->codecpar->width - 1);
118  bytestream_put_le24(&bufp, st->codecpar->height - 1);
119  }
120  if (!trailer) {
121  bytestream_put_le32(&bufp, MKTAG('A', 'N', 'I', 'M'));
122  bytestream_put_le32(&bufp, 6);
123  bytestream_put_le32(&bufp, 0xFFFFFFFF);
124  bytestream_put_le16(&bufp, w->loop);
125  }
126  }
127 
128  if (w->frame_count > trailer) {
129  bytestream_put_le32(&bufp, MKTAG('A', 'N', 'M', 'F'));
130  bytestream_put_le32(&bufp, 16 + w->last_pkt->size - skip);
131  bytestream_put_le24(&bufp, 0);
132  bytestream_put_le24(&bufp, 0);
133  bytestream_put_le24(&bufp, st->codecpar->width - 1);
134  bytestream_put_le24(&bufp, st->codecpar->height - 1);
135  if (w->last_pkt->pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE) {
136  bytestream_put_le24(&bufp, pts - w->last_pkt->pts);
137  } else
138  bytestream_put_le24(&bufp, w->last_pkt->duration);
139  bytestream_put_byte(&bufp, 0);
140  }
141  if (trailer && writing_webp_header)
142  AV_WL32(buf + 4, bufp - (buf + 8) + w->last_pkt->size - skip);
143  avio_write(s->pb, buf, bufp - buf);
144  avio_write(s->pb, w->last_pkt->data + skip, w->last_pkt->size - skip);
145  av_packet_unref(w->last_pkt);
146 
147  return trailer && writing_webp_header;
148 }
149 
151 {
152  WebpContext *w = s->priv_data;
153  int ret;
154 
155  if (!pkt->size)
156  return 0;
158  if (ret < 0)
159  return ret;
160  w->using_webp_anim_encoder |= ret;
161 
162  if (w->using_webp_anim_encoder) {
163  avio_write(s->pb, pkt->data, pkt->size);
164  w->wrote_webp_header = 1; // for good measure
165  } else {
166  int ret;
167  if ((ret = flush(s, 0, pkt->pts)) < 0)
168  return ret;
169  av_packet_ref(w->last_pkt, pkt);
170  }
171  ++w->frame_count;
172 
173  return 0;
174 }
175 
177 {
178  unsigned filesize;
179  WebpContext *w = s->priv_data;
180 
181  if (w->using_webp_anim_encoder) {
182  if (w->loop) { // Write loop count.
183  if (avio_seek(s->pb, 42, SEEK_SET) == 42)
184  avio_wl16(s->pb, w->loop);
185  }
186  } else {
187  int ret;
188  if ((ret = flush(s, 1, AV_NOPTS_VALUE)) < 0)
189  return ret;
190 
191  if (!ret) {
192  filesize = avio_tell(s->pb);
193  if (avio_seek(s->pb, 4, SEEK_SET) == 4) {
194  avio_wl32(s->pb, filesize - 8);
195  // Note: without the following, avio only writes 8 bytes to the file.
196  avio_seek(s->pb, filesize, SEEK_SET);
197  }
198  }
199  }
200 
201  return 0;
202 }
203 
204 #define OFFSET(x) offsetof(WebpContext, x)
205 #define ENC AV_OPT_FLAG_ENCODING_PARAM
206 static const AVOption options[] = {
207  { "loop", "Number of times to loop the output: 0 - infinite loop", OFFSET(loop),
208  AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 65535, ENC },
209  { NULL },
210 };
211 
212 static const AVClass webp_muxer_class = {
213  .class_name = "WebP muxer",
214  .item_name = av_default_item_name,
215  .version = LIBAVUTIL_VERSION_INT,
216  .option = options,
217 };
219  .p.name = "webp",
220  .p.long_name = NULL_IF_CONFIG_SMALL("WebP"),
221  .p.extensions = "webp",
222  .priv_data_size = sizeof(WebpContext),
223  .p.video_codec = AV_CODEC_ID_WEBP,
224  .p.audio_codec = AV_CODEC_ID_NONE,
225  .p.subtitle_codec = AV_CODEC_ID_NONE,
226  .init = webp_init,
227  .write_packet = webp_write_packet,
228  .write_trailer = webp_write_trailer,
229  .p.priv_class = &webp_muxer_class,
230  .p.flags = AVFMT_VARIABLE_FPS,
231  .flags_internal = FF_OFMT_FLAG_MAX_ONE_OF_EACH |
233 };
ENC
#define ENC
Definition: webpenc.c:205
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: packet.c:428
AVOutputFormat::name
const char * name
Definition: avformat.h:510
opt.h
WebpContext::using_webp_anim_encoder
int using_webp_anim_encoder
Definition: webpenc.c:35
AV_WL32
#define AV_WL32(p, v)
Definition: intreadwrite.h:420
ffformatcontext
static av_always_inline FFFormatContext * ffformatcontext(AVFormatContext *s)
Definition: internal.h:188
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:482
WebpContext::frame_count
int frame_count
Definition: webpenc.c:31
int64_t
long long int64_t
Definition: coverity.c:34
WebpContext::wrote_webp_header
int wrote_webp_header
Definition: webpenc.c:34
w
uint8_t w
Definition: llviddspenc.c:38
AVPacket::data
uint8_t * data
Definition: packet.h:533
AVOption
AVOption.
Definition: opt.h:357
FF_OFMT_FLAG_ONLY_DEFAULT_CODECS
#define FF_OFMT_FLAG_ONLY_DEFAULT_CODECS
If this flag is set, then the only permitted audio/video/subtitle codec ids are AVOutputFormat....
Definition: mux.h:59
FFOutputFormat::p
AVOutputFormat p
The public AVOutputFormat.
Definition: mux.h:65
avio_wl16
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:437
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:855
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:494
pts
static int64_t pts
Definition: transcode_aac.c:644
loop
static int loop
Definition: ffplay.c:335
options
static const AVOption options[]
Definition: webpenc.c:206
pkt
AVPacket * pkt
Definition: movenc.c:60
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
AVFormatContext
Format I/O context.
Definition: avformat.h:1260
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:771
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
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
FFOutputFormat
Definition: mux.h:61
av_packet_ref
int av_packet_ref(AVPacket *dst, const AVPacket *src)
Setup a new reference to the data described by a given packet.
Definition: packet.c:436
AVPacket::size
int size
Definition: packet.h:534
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:94
is_animated_webp_packet
static int is_animated_webp_packet(AVPacket *pkt)
Definition: webpenc.c:50
WebpContext::last_pkt
AVPacket * last_pkt
Definition: webpenc.c:32
AV_NOPTS_VALUE
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
avio_write
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:201
avio_wl32
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:357
webp_muxer_class
static const AVClass webp_muxer_class
Definition: webpenc.c:212
filesize
static int64_t filesize(AVIOContext *pb)
Definition: ffmpeg_mux.c:51
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:50
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:526
AVCodecParameters::height
int height
Definition: codec_par.h:135
flush
static int flush(AVFormatContext *s, int trailer, int64_t pts)
Returns 1 if it has written a RIFF header with a correct length field.
Definition: webpenc.c:74
webp_write_packet
static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: webpenc.c:150
FF_OFMT_FLAG_MAX_ONE_OF_EACH
#define FF_OFMT_FLAG_MAX_ONE_OF_EACH
If this flag is set, it indicates that for each codec type whose corresponding default codec (i....
Definition: mux.h:50
WebpContext::loop
int loop
Definition: webpenc.c:33
AV_CODEC_ID_WEBP
@ AV_CODEC_ID_WEBP
Definition: codec_id.h:224
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:748
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:231
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
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:245
ff_webp_muxer
const FFOutputFormat ff_webp_muxer
Definition: webpenc.c:218
FFFormatContext::pkt
AVPacket * pkt
Used to hold temporary packets for the generic demuxing code.
Definition: internal.h:134
AVPacket
This structure stores compressed data.
Definition: packet.h:510
webp_init
static int webp_init(AVFormatContext *s)
Definition: webpenc.c:38
bytestream.h
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:474
WebpContext
Definition: webpenc.c:29
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
OFFSET
#define OFFSET(x)
Definition: webpenc.c:204
skip
static void BS_FUNC() skip(BSCTX *bc, unsigned int n)
Skip n bits in the buffer.
Definition: bitstream_template.h:375
webp_write_trailer
static int webp_write_trailer(AVFormatContext *s)
Definition: webpenc.c:176
mux.h