| /********** |
| This library is free software; you can redistribute it and/or modify it under |
| the terms of the GNU Lesser General Public License as published by the |
| Free Software Foundation; either version 3 of the License, or (at your |
| option) any later version. (See <http://www.gnu.org/copyleft/lesser.html>.) |
| |
| This library 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 Lesser General Public License for |
| more details. |
| |
| You should have received a copy of the GNU Lesser General Public License |
| along with this library; if not, write to the Free Software Foundation, Inc., |
| 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| **********/ |
| // "liveMedia" |
| // Copyright (c) 1996-2020 Live Networks, Inc. All rights reserved. |
| // A class for streaming data from a (static) memory buffer, as if it were a file. |
| // Implementation |
| |
| #include "ByteStreamMemoryBufferSource.hh" |
| #include "GroupsockHelper.hh" |
| |
| ////////// ByteStreamMemoryBufferSource ////////// |
| |
| ByteStreamMemoryBufferSource* |
| ByteStreamMemoryBufferSource::createNew(UsageEnvironment& env, |
| u_int8_t* buffer, u_int64_t bufferSize, |
| Boolean deleteBufferOnClose, |
| unsigned preferredFrameSize, |
| unsigned playTimePerFrame) { |
| if (buffer == NULL) return NULL; |
| |
| return new ByteStreamMemoryBufferSource(env, buffer, bufferSize, deleteBufferOnClose, preferredFrameSize, playTimePerFrame); |
| } |
| |
| ByteStreamMemoryBufferSource::ByteStreamMemoryBufferSource(UsageEnvironment& env, |
| u_int8_t* buffer, u_int64_t bufferSize, |
| Boolean deleteBufferOnClose, |
| unsigned preferredFrameSize, |
| unsigned playTimePerFrame) |
| : FramedSource(env), fBuffer(buffer), fBufferSize(bufferSize), fCurIndex(0), fDeleteBufferOnClose(deleteBufferOnClose), |
| fPreferredFrameSize(preferredFrameSize), fPlayTimePerFrame(playTimePerFrame), fLastPlayTime(0), |
| fLimitNumBytesToStream(False), fNumBytesToStream(0) { |
| } |
| |
| ByteStreamMemoryBufferSource::~ByteStreamMemoryBufferSource() { |
| if (fDeleteBufferOnClose) delete[] fBuffer; |
| } |
| |
| void ByteStreamMemoryBufferSource::seekToByteAbsolute(u_int64_t byteNumber, u_int64_t numBytesToStream) { |
| fCurIndex = byteNumber; |
| if (fCurIndex > fBufferSize) fCurIndex = fBufferSize; |
| |
| fNumBytesToStream = numBytesToStream; |
| fLimitNumBytesToStream = fNumBytesToStream > 0; |
| } |
| |
| void ByteStreamMemoryBufferSource::seekToByteRelative(int64_t offset, u_int64_t numBytesToStream) { |
| int64_t newIndex = fCurIndex + offset; |
| if (newIndex < 0) { |
| fCurIndex = 0; |
| } else { |
| fCurIndex = (u_int64_t)offset; |
| if (fCurIndex > fBufferSize) fCurIndex = fBufferSize; |
| } |
| |
| fNumBytesToStream = numBytesToStream; |
| fLimitNumBytesToStream = fNumBytesToStream > 0; |
| } |
| |
| void ByteStreamMemoryBufferSource::doGetNextFrame() { |
| if (fCurIndex >= fBufferSize || (fLimitNumBytesToStream && fNumBytesToStream == 0)) { |
| handleClosure(); |
| return; |
| } |
| |
| // Try to read as many bytes as will fit in the buffer provided (or "fPreferredFrameSize" if less) |
| fFrameSize = fMaxSize; |
| if (fLimitNumBytesToStream && fNumBytesToStream < (u_int64_t)fFrameSize) { |
| fFrameSize = (unsigned)fNumBytesToStream; |
| } |
| if (fPreferredFrameSize > 0 && fPreferredFrameSize < fFrameSize) { |
| fFrameSize = fPreferredFrameSize; |
| } |
| |
| if (fCurIndex + fFrameSize > fBufferSize) { |
| fFrameSize = (unsigned)(fBufferSize - fCurIndex); |
| } |
| |
| memmove(fTo, &fBuffer[fCurIndex], fFrameSize); |
| fCurIndex += fFrameSize; |
| fNumBytesToStream -= fFrameSize; |
| |
| // Set the 'presentation time': |
| if (fPlayTimePerFrame > 0 && fPreferredFrameSize > 0) { |
| if (fPresentationTime.tv_sec == 0 && fPresentationTime.tv_usec == 0) { |
| // This is the first frame, so use the current time: |
| gettimeofday(&fPresentationTime, NULL); |
| } else { |
| // Increment by the play time of the previous data: |
| unsigned uSeconds = fPresentationTime.tv_usec + fLastPlayTime; |
| fPresentationTime.tv_sec += uSeconds/1000000; |
| fPresentationTime.tv_usec = uSeconds%1000000; |
| } |
| |
| // Remember the play time of this data: |
| fLastPlayTime = (fPlayTimePerFrame*fFrameSize)/fPreferredFrameSize; |
| fDurationInMicroseconds = fLastPlayTime; |
| } else { |
| // We don't know a specific play time duration for this data, |
| // so just record the current time as being the 'presentation time': |
| gettimeofday(&fPresentationTime, NULL); |
| } |
| |
| // Inform the downstream object that it has data: |
| FramedSource::afterGetting(this); |
| } |