1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
|
// GoToSocial
// Copyright (C) GoToSocial Authors admin@gotosocial.org
// SPDX-License-Identifier: AGPL-3.0-or-later
//
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program. If not, see <http://www.gnu.org/licenses/>.
package media
import (
"fmt"
"io"
"github.com/abema/go-mp4"
"github.com/superseriousbusiness/gotosocial/internal/iotools"
"github.com/superseriousbusiness/gotosocial/internal/log"
)
type gtsVideo struct {
frame *gtsImage
duration float32 // in seconds
bitrate uint64
framerate float32
}
// decodeVideoFrame decodes and returns an image from a single frame in the given video stream.
// (note: currently this only returns a blank image resized to fit video dimensions).
func decodeVideoFrame(r io.Reader) (*gtsVideo, error) {
// we need a readseeker to decode the video...
tfs, err := iotools.TempFileSeeker(r)
if err != nil {
return nil, fmt.Errorf("error creating temp file seeker: %w", err)
}
defer func() {
if err := tfs.Close(); err != nil {
log.Errorf(nil, "error closing temp file seeker: %s", err)
}
}()
// probe the video file to extract useful metadata from it; for methodology, see:
// https://github.com/abema/go-mp4/blob/7d8e5a7c5e644e0394261b0cf72fef79ce246d31/mp4tool/probe/probe.go#L85-L154
info, err := mp4.Probe(tfs)
if err != nil {
return nil, fmt.Errorf("error during mp4 probe: %w", err)
}
var (
width int
height int
videoBitrate uint64
audioBitrate uint64
video gtsVideo
)
for _, tr := range info.Tracks {
if tr.AVC == nil {
// audio track
if br := tr.Samples.GetBitrate(tr.Timescale); br > audioBitrate {
audioBitrate = br
} else if br := info.Segments.GetBitrate(tr.TrackID, tr.Timescale); br > audioBitrate {
audioBitrate = br
}
if d := float64(tr.Duration) / float64(tr.Timescale); d > float64(video.duration) {
video.duration = float32(d)
}
continue
}
// video track
if w := int(tr.AVC.Width); w > width {
width = w
}
if h := int(tr.AVC.Height); h > height {
height = h
}
if br := tr.Samples.GetBitrate(tr.Timescale); br > videoBitrate {
videoBitrate = br
} else if br := info.Segments.GetBitrate(tr.TrackID, tr.Timescale); br > videoBitrate {
videoBitrate = br
}
if d := float64(tr.Duration) / float64(tr.Timescale); d > float64(video.duration) {
video.framerate = float32(len(tr.Samples)) / float32(d)
video.duration = float32(d)
}
}
// overall bitrate should be audio + video combined
// (since they're both playing at the same time)
video.bitrate = audioBitrate + videoBitrate
// Check for empty video metadata.
var empty []string
if width == 0 {
empty = append(empty, "width")
}
if height == 0 {
empty = append(empty, "height")
}
if video.duration == 0 {
empty = append(empty, "duration")
}
if video.framerate == 0 {
empty = append(empty, "framerate")
}
if video.bitrate == 0 {
empty = append(empty, "bitrate")
}
if len(empty) > 0 {
return nil, fmt.Errorf("error determining video metadata: %v", empty)
}
// Create new empty "frame" image.
// TODO: decode frame from video file.
video.frame = blankImage(width, height)
return &video, nil
}
|
