Hey,
Im writing a program where I have to use custom IO Callbacks because I
have to play video files with a prepended extra header. However, if I
try to play a movie with an offset of e.g. 10 bytes and I seek, the
movie might play on, but audio doesnt:
[h264 @ 0x240afc0] left block unavailable for requested intra mode at 0 17
[h264 @ 0x240afc0] error while decoding MB 0 17
[h264 @ 0x240afc0] AVC: nal size 399
[h264 @ 0x240afc0] concealing 229 DC, 229 AC, 229 MV errors
[h264 @ 0x240afc0] AVC: nal size 25153
[h264 @ 0x240afc0] no frame!
packet didnt contain a complete frame!
[aac @ 0x20220a0] channel element 2.14 is not allocated
This happens sporadic and I cant figure out why. My Seek_Func just calls
a subclassed QFile::seek(...) which returns QFile::seek(... + offset ).
Has anybody an Idea why seek often doesnt work? Maybe I am missing a
parameter when I create my callback? Btw: The format is recognized
correctly, also without seeking the video is played correctly...
Many thanks,
Christoph Winter
MController.cpp:
ioContext = avio_alloc_context(buffer, BUFFER_SIZE, 0, fileReader,
ReadFunc, NULL, SeekFunc);
ioContext->write_flag = 0;
ioContext->is_streamed = 1;
ioContext->seekable = 1;
MFile.cpp:
bool MFile::seek(qint64 offset)
{
return QFile::seek(offset+10);
}
Utils.h:
int64_t SeekFunc(void *opaque, int64_t offset, int whence)
{
qDebug() << "SeekFunc offset=" << offset << " whence=" << whence;
QIODevice *io = (MFile*)opaque;
int64_t absolute_pos = 0;
switch(whence)
{
case AVSEEK_SIZE:
return io->size();
case SEEK_SET:
absolute_pos = offset;
break;
case SEEK_CUR:
absolute_pos = io->pos() + offset;
case SEEK_END:
absolute_pos = io->size() - offset;
default:
return -1;
}
if( absolute_pos < 0 || absolute_pos > io->size() )
return -1;
bool ret = io->seek(absolute_pos);
return ret;
}
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