// The total number of frames for the image. Will scan the image data for the answer
// (without necessarily decoding all of the individual frames).
int GIFImageDecoder::frameCount()
{
// If the decoder had an earlier error, we will just return what we had decoded
// so far.
if (!m_frameCountValid) {
// FIXME: Scanning all the data has O(n^2) behavior if the data were to come in really
// slowly. Might be interesting to try to clone our existing read session to preserve
// state, but for now we just crawl all the data. Note that this is no worse than what
// ImageIO does on Mac right now (it also crawls all the data again).
GIFImageDecoderPrivate reader;
reader.decode(m_data, GIFFrameCountQuery);
m_frameCountValid = true;
m_frameBufferCache.resize(reader.frameCount());
}
return m_frameBufferCache.size();
}
// The total number of frames for the image. Will scan the image data for the answer
// (without necessarily decoding all of the individual frames).
size_t GIFImageDecoder::frameCount()
{
// If the decoder had an earlier error, we will just return what we had decoded
// so far.
if (!m_frameCountValid) {
// FIXME: Scanning all the data has O(n^2) behavior if the data were to come in really
// slowly. Might be interesting to try to clone our existing read session to preserve
// state, but for now we just crawl all the data. Note that this is no worse than what
// ImageIO does on Mac right now (it also crawls all the data again).
GIFImageDecoderPrivate reader;
// This function may fail, but we want to keep any partial data it may
// have decoded, so don't mark it is invalid. If there is an overflow
// or some serious error, m_failed will have gotten set for us.
reader.decode(m_data, GIFFrameCountQuery);
m_frameCountValid = true;
m_frameBufferCache.resize(reader.frameCount());
m_rects.resize(reader.frameCount());
}
return m_frameBufferCache.size();
}
