FFmpeg: libavformat/webpenc.c Source File

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 "avformat.h"
25 #include "internal.h"
26 
27  typedef struct WebpContext{
28   AVClass *class;
29   int frame_count;
30   AVPacket *last_pkt; /* Not owned by us */
31   int loop;
32   int wrote_webp_header;
33   int using_webp_anim_encoder;
34 } WebpContext;
35 
36  static int webp_init(AVFormatContext *s)
37 {
38  WebpContext *const w = s->priv_data;
39  AVStream *st;
40 
41  w->last_pkt = ffformatcontext(s)->pkt;
42 
43  if (s->nb_streams != 1) {
44  av_log(s, AV_LOG_ERROR, "Only exactly 1 stream is supported\n");
45  return AVERROR(EINVAL);
46  }
47  st = s->streams[0];
48  if (st->codecpar->codec_id != AV_CODEC_ID_WEBP) {
49  av_log(s, AV_LOG_ERROR, "Only WebP is supported\n");
50  return AVERROR(EINVAL);
51  }
52  avpriv_set_pts_info(st, 24, 1, 1000);
53 
54  return 0;
55 }
56 
57  static int is_animated_webp_packet(AVPacket *pkt)
58 {
59  int skip = 0;
60  unsigned flags = 0;
61 
62  if (pkt->size < 4)
63  return AVERROR_INVALIDDATA;
64  if (AV_RL32(pkt->data) == AV_RL32("RIFF"))
65  skip = 12;
66  // Safe to do this as a valid WebP bitstream is >=30 bytes.
67  if (pkt->size < skip + 4)
68  return AVERROR_INVALIDDATA;
69  if (AV_RL32(pkt->data + skip) == AV_RL32("VP8X")) {
70  flags |= pkt->data[skip + 4 + 4];
71  }
72 
73  if (flags & 2) // ANIMATION_FLAG is on
74  return 1;
75  return 0;
76 }
77 
78  static int flush(AVFormatContext *s, int trailer, int64_t pts)
79 {
80  WebpContext *w = s->priv_data;
81  AVStream *st = s->streams[0];
82 
83  if (w->last_pkt->size) {
84  int skip = 0;
85  unsigned flags = 0;
86  int vp8x = 0;
87 
88  if (AV_RL32(w->last_pkt->data) == AV_RL32("RIFF"))
89  skip = 12;
90 
91  if (AV_RL32(w->last_pkt->data + skip) == AV_RL32("VP8X")) {
92  flags |= w->last_pkt->data[skip + 4 + 4];
93  vp8x = 1;
94  skip += AV_RL32(w->last_pkt->data + skip + 4) + 8;
95  }
96 
97  if (!w->wrote_webp_header) {
98  avio_write(s->pb, "RIFF0円0円0円0円WEBP", 12);
99  w->wrote_webp_header = 1;
100  if (w->frame_count > 1) // first non-empty packet
101  w->frame_count = 1; // so we don't count previous empty packets.
102  }
103 
104  if (w->frame_count == 1) {
105  if (!trailer) {
106  vp8x = 1;
107  flags |= 2 + 16;
108  }
109 
110  if (vp8x) {
111  avio_write(s->pb, "VP8X", 4);
112  avio_wl32(s->pb, 10);
113  avio_w8(s->pb, flags);
114  avio_wl24(s->pb, 0);
115  avio_wl24(s->pb, st->codecpar->width - 1);
116  avio_wl24(s->pb, st->codecpar->height - 1);
117  }
118  if (!trailer) {
119  avio_write(s->pb, "ANIM", 4);
120  avio_wl32(s->pb, 6);
121  avio_wl32(s->pb, 0xFFFFFFFF);
122  avio_wl16(s->pb, w->loop);
123  }
124  }
125 
126  if (w->frame_count > trailer) {
127  avio_write(s->pb, "ANMF", 4);
128  avio_wl32(s->pb, 16 + w->last_pkt->size - skip);
129  avio_wl24(s->pb, 0);
130  avio_wl24(s->pb, 0);
131  avio_wl24(s->pb, st->codecpar->width - 1);
132  avio_wl24(s->pb, st->codecpar->height - 1);
133  if (w->last_pkt->pts != AV_NOPTS_VALUE && pts != AV_NOPTS_VALUE) {
134  avio_wl24(s->pb, pts - w->last_pkt->pts);
135  } else
136  avio_wl24(s->pb, w->last_pkt->duration);
137  avio_w8(s->pb, 0);
138  }
139  avio_write(s->pb, w->last_pkt->data + skip, w->last_pkt->size - skip);
140  av_packet_unref(w->last_pkt);
141  }
142 
143  return 0;
144 }
145 
146  static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
147 {
148  WebpContext *w = s->priv_data;
149  int ret;
150 
151  if (!pkt->size)
152  return 0;
153  ret = is_animated_webp_packet(pkt);
154  if (ret < 0)
155  return ret;
156  w->using_webp_anim_encoder |= ret;
157 
158  if (w->using_webp_anim_encoder) {
159  avio_write(s->pb, pkt->data, pkt->size);
160  w->wrote_webp_header = 1; // for good measure
161  } else {
162  int ret;
163  if ((ret = flush(s, 0, pkt->pts)) < 0)
164  return ret;
165  av_packet_ref(w->last_pkt, pkt);
166  }
167  ++w->frame_count;
168 
169  return 0;
170 }
171 
172  static int webp_write_trailer(AVFormatContext *s)
173 {
174  unsigned filesize;
175  WebpContext *w = s->priv_data;
176 
177  if (w->using_webp_anim_encoder) {
178  if (w->loop) { // Write loop count.
179  avio_seek(s->pb, 42, SEEK_SET);
180  avio_wl16(s->pb, w->loop);
181  }
182  } else {
183  int ret;
184  if ((ret = flush(s, 1, AV_NOPTS_VALUE)) < 0)
185  return ret;
186 
187  filesize = avio_tell(s->pb);
188  avio_seek(s->pb, 4, SEEK_SET);
189  avio_wl32(s->pb, filesize - 8);
190  // Note: without the following, avio only writes 8 bytes to the file.
191  avio_seek(s->pb, filesize, SEEK_SET);
192  }
193 
194  return 0;
195 }
196 
197  #define OFFSET(x) offsetof(WebpContext, x)
198  #define ENC AV_OPT_FLAG_ENCODING_PARAM
199  static const AVOption options[] = {
200  { "loop", "Number of times to loop the output: 0 - infinite loop", OFFSET(loop),
201  AV_OPT_TYPE_INT, { .i64 = 1 }, 0, 65535, ENC },
202  { NULL },
203 };
204 
205  static const AVClass webp_muxer_class = {
206  .class_name = "WebP muxer",
207  .item_name = av_default_item_name,
208  .version = LIBAVUTIL_VERSION_INT,
209  .option = options,
210 };
211  const AVOutputFormat ff_webp_muxer = {
212  .name = "webp",
213  .long_name = NULL_IF_CONFIG_SMALL("WebP"),
214  .extensions = "webp",
215  .priv_data_size = sizeof(WebpContext),
216  .video_codec = AV_CODEC_ID_WEBP,
217  .init = webp_init,
218  .write_packet = webp_write_packet,
219  .write_trailer = webp_write_trailer,
220  .priv_class = &webp_muxer_class,
221  .flags = AVFMT_VARIABLE_FPS,
222 };
ENC
#define ENC
Definition: webpenc.c:198
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:422
AVOutputFormat::name
const char * name
Definition: avformat.h:510
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
WebpContext::using_webp_anim_encoder
int using_webp_anim_encoder
Definition: webpenc.c:33
ffformatcontext
static av_always_inline FFFormatContext * ffformatcontext(AVFormatContext *s)
Definition: internal.h:192
AVFMT_VARIABLE_FPS
#define AVFMT_VARIABLE_FPS
Format allows variable fps.
Definition: avformat.h:484
WebpContext::frame_count
int frame_count
Definition: webpenc.c:29
WebpContext::wrote_webp_header
int wrote_webp_header
Definition: webpenc.c:32
w
uint8_t w
Definition: llviddspenc.c:38
AVPacket::data
uint8_t * data
Definition: packet.h:374
AVOption
AVOption.
Definition: opt.h:251
ff_webp_muxer
const AVOutputFormat ff_webp_muxer
Definition: webpenc.c:211
init
static int init
Definition: av_tx.c:47
avio_wl16
void avio_wl16(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:466
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:697
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:505
pts
static int64_t pts
Definition: transcode_aac.c:654
loop
static int loop
Definition: ffplay.c:340
options
static const AVOption options[]
Definition: webpenc.c:199
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
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:256
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:127
AVFormatContext
Format I/O context.
Definition: avformat.h:1213
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1108
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
write_trailer
static int write_trailer(AVFormatContext *s1)
Definition: v4l2enc.c:100
av_default_item_name
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:237
avio_w8
void avio_w8(AVIOContext *s, int b)
Definition: aviobuf.c:210
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: avpacket.c:430
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
is_animated_webp_packet
static int is_animated_webp_packet(AVPacket *pkt)
Definition: webpenc.c:57
WebpContext::last_pkt
AVPacket * last_pkt
Definition: webpenc.c:30
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:232
avio_wl32
void avio_wl32(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:386
webp_muxer_class
static const AVClass webp_muxer_class
Definition: webpenc.c:205
AVOutputFormat
Definition: avformat.h:509
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:367
AVCodecParameters::height
int height
Definition: codec_par.h:128
flush
static int flush(AVFormatContext *s, int trailer, int64_t pts)
Definition: webpenc.c:78
webp_write_packet
static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
Definition: webpenc.c:146
WebpContext::loop
int loop
Definition: webpenc.c:31
AV_CODEC_ID_WEBP
@ AV_CODEC_ID_WEBP
Definition: codec_id.h:222
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:948
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:260
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:225
FFFormatContext::pkt
AVPacket * pkt
Used to hold temporary packets for the generic demuxing code.
Definition: internal.h:142
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:61
AVPacket
This structure stores compressed data.
Definition: packet.h:351
webp_init
static int webp_init(AVFormatContext *s)
Definition: webpenc.c:36
flags
#define flags(name, subs,...)
Definition: cbs_av1.c:561
WebpContext
Definition: webpenc.c:27
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
avio_wl24
void avio_wl24(AVIOContext *s, unsigned int val)
Definition: aviobuf.c:478
write_packet
static int write_packet(AVFormatContext *s1, AVPacket *pkt)
Definition: v4l2enc.c:92
OFFSET
#define OFFSET(x)
Definition: webpenc.c:197
webp_write_trailer
static int webp_write_trailer(AVFormatContext *s)
Definition: webpenc.c:172
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