FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavformat/webpenc.c
Date: 2024-05-03 15:42:48
Exec Total Coverage
Lines: 0 106 0.0%
Functions: 0 5 0.0%
Branches: 0 62 0.0%

Line Branch Exec Source
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;
31 int frame_count;
32 AVPacket *last_pkt; /* Not owned by us */
33 int loop;
34 int wrote_webp_header;
35 int using_webp_anim_encoder;
36 } WebpContext;
37
38 static int webp_init(AVFormatContext *s)
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
50 static int is_animated_webp_packet(AVPacket *pkt)
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
150 static int webp_write_packet(AVFormatContext *s, AVPacket *pkt)
151 {
152 WebpContext *w = s->priv_data;
153 int ret;
154
155 if (!pkt->size)
156 return 0;
157 ret = is_animated_webp_packet(pkt);
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
176 static int webp_write_trailer(AVFormatContext *s)
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 };
218 const FFOutputFormat ff_webp_muxer = {
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 |
232 FF_OFMT_FLAG_ONLY_DEFAULT_CODECS,
233 };
234