wxImage wxFfmpegMediaDecoder::GetNextFrame() {
if (!m_frame && !BeginDecode())
return wxImage();
int frameFinished;
AVPacket packet;
while (av_read_frame(m_formatCtx, &packet) >=0) {
// is this a packet from the video stream?
if (packet.stream_index == m_videoStream) {
// decode video frame
avcodec_decode_video2(m_codecCtx, m_frame, &frameFinished, &packet);
if (frameFinished) {
SwsContext* imgConvertCtx = sws_getContext(m_codecCtx->width, m_codecCtx->height, m_codecCtx->pix_fmt,
m_width, m_height, AV_PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
if (imgConvertCtx == NULL) {
av_packet_unref(&packet);
return wxImage();
}
wxImage img(m_width, m_height);
uint8_t *rgbSrc[3] = { img.GetData(), NULL, NULL };
int rgbStride[3] = { 3 * m_width, 0, 0 };
sws_scale(imgConvertCtx, m_frame->data, m_frame->linesize, 0, m_codecCtx->height, rgbSrc, rgbStride);
av_packet_unref(&packet);
sws_freeContext(imgConvertCtx);
return img;
}
}
// free the packet that was allocated by av_read_frame
av_packet_unref(&packet);
}
return wxImage();
}
inline unsigned const * IlbmBodyChunk::DecodeFirstRow() const
{
if (BeginDecode())
return DecodeNextRow();
else
return NULL;
}
bool wxFfmpegMediaDecoder::SetPosition(double pos, bool keyFrame) {
if (m_formatCtx == NULL)
return false;
if (!m_frame && !BeginDecode())
return false;
int64_t timestamp = (int64_t) (pos * AV_TIME_BASE);
if (m_formatCtx->start_time != (int64_t)AV_NOPTS_VALUE)
timestamp += m_formatCtx->start_time;
avcodec_flush_buffers(m_codecCtx);
bool res = av_seek_frame(m_formatCtx, -1, timestamp,
keyFrame ? AVSEEK_FLAG_BACKWARD : AVSEEK_FLAG_ANY|AVSEEK_FLAG_BACKWARD) >= 0;
avcodec_flush_buffers(m_codecCtx);
return res;
}
