1/**********
2This library is free software; you can redistribute it and/or modify it under
3the terms of the GNU Lesser General Public License as published by the
4Free Software Foundation; either version 3 of the License, or (at your
5option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.)
6
7This library is distributed in the hope that it will be useful, but WITHOUT
8ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
9FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License for
10more details.
11
12You should have received a copy of the GNU Lesser General Public License
13along with this library; if not, write to the Free Software Foundation, Inc.,
1451 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
15**********/
16// "liveMedia"
17// Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved.
18// A class for streaming data from a (static) memory buffer, as if it were a file.
19// Implementation
20
21#include "ByteStreamMemoryBufferSource.hh"
22#include "GroupsockHelper.hh"
23
24////////// ByteStreamMemoryBufferSource //////////
25
26ByteStreamMemoryBufferSource*
27ByteStreamMemoryBufferSource::createNew(UsageEnvironment& env,
28 u_int8_t* buffer, u_int64_t bufferSize,
29 Boolean deleteBufferOnClose,
30 unsigned preferredFrameSize,
31 unsigned playTimePerFrame) {
32 if (buffer == NULL) return NULL;
33
34 return new ByteStreamMemoryBufferSource(env, buffer, bufferSize, deleteBufferOnClose, preferredFrameSize, playTimePerFrame);
35}
36
37ByteStreamMemoryBufferSource::ByteStreamMemoryBufferSource(UsageEnvironment& env,
38 u_int8_t* buffer, u_int64_t bufferSize,
39 Boolean deleteBufferOnClose,
40 unsigned preferredFrameSize,
41 unsigned playTimePerFrame)
42 : FramedSource(env), fBuffer(buffer), fBufferSize(bufferSize), fCurIndex(0), fDeleteBufferOnClose(deleteBufferOnClose),
43 fPreferredFrameSize(preferredFrameSize), fPlayTimePerFrame(playTimePerFrame), fLastPlayTime(0),
44 fLimitNumBytesToStream(False), fNumBytesToStream(0) {
45}
46
47ByteStreamMemoryBufferSource::~ByteStreamMemoryBufferSource() {
48 if (fDeleteBufferOnClose) delete[] fBuffer;
49}
50
51void ByteStreamMemoryBufferSource::seekToByteAbsolute(u_int64_t byteNumber, u_int64_t numBytesToStream) {
52 fCurIndex = byteNumber;
53 if (fCurIndex > fBufferSize) fCurIndex = fBufferSize;
54
55 fNumBytesToStream = numBytesToStream;
56 fLimitNumBytesToStream = fNumBytesToStream > 0;
57}
58
59void ByteStreamMemoryBufferSource::seekToByteRelative(int64_t offset, u_int64_t numBytesToStream) {
60 int64_t newIndex = fCurIndex + offset;
61 if (newIndex < 0) {
62 fCurIndex = 0;
63 } else {
64 fCurIndex = (u_int64_t)offset;
65 if (fCurIndex > fBufferSize) fCurIndex = fBufferSize;
66 }
67
68 fNumBytesToStream = numBytesToStream;
69 fLimitNumBytesToStream = fNumBytesToStream > 0;
70}
71
72void ByteStreamMemoryBufferSource::doGetNextFrame() {
73 if (fCurIndex >= fBufferSize || (fLimitNumBytesToStream && fNumBytesToStream == 0)) {
74 handleClosure();
75 return;
76 }
77
78 // Try to read as many bytes as will fit in the buffer provided (or "fPreferredFrameSize" if less)
79 fFrameSize = fMaxSize;
80 if (fLimitNumBytesToStream && fNumBytesToStream < (u_int64_t)fFrameSize) {
81 fFrameSize = (unsigned)fNumBytesToStream;
82 }
83 if (fPreferredFrameSize > 0 && fPreferredFrameSize < fFrameSize) {
84 fFrameSize = fPreferredFrameSize;
85 }
86
87 if (fCurIndex + fFrameSize > fBufferSize) {
88 fFrameSize = (unsigned)(fBufferSize - fCurIndex);
89 }
90
91 memmove(fTo, &fBuffer[fCurIndex], fFrameSize);
92 fCurIndex += fFrameSize;
93 fNumBytesToStream -= fFrameSize;
94
95 // Set the 'presentation time':
96 if (fPlayTimePerFrame > 0 && fPreferredFrameSize > 0) {
97 if (fPresentationTime.tv_sec == 0 && fPresentationTime.tv_usec == 0) {
98 // This is the first frame, so use the current time:
99 gettimeofday(&fPresentationTime, NULL);
100 } else {
101 // Increment by the play time of the previous data:
102 unsigned uSeconds = fPresentationTime.tv_usec + fLastPlayTime;
103 fPresentationTime.tv_sec += uSeconds/1000000;
104 fPresentationTime.tv_usec = uSeconds%1000000;
105 }
106
107 // Remember the play time of this data:
108 fLastPlayTime = (fPlayTimePerFrame*fFrameSize)/fPreferredFrameSize;
109 fDurationInMicroseconds = fLastPlayTime;
110 } else {
111 // We don't know a specific play time duration for this data,
112 // so just record the current time as being the 'presentation time':
113 gettimeofday(&fPresentationTime, NULL);
114 }
115
116 // Inform the downstream object that it has data:
117 FramedSource::afterGetting(this);
118}
119