// main entry point int VP8EncAnalyze(VP8Encoder* const enc) { int ok = 1; const int do_segments = enc->config_->emulate_jpeg_size || // We need the complexity evaluation. (enc->segment_hdr_.num_segments_ > 1) || (enc->method_ == 0); // for method 0, we need preds_[] to be filled. if (do_segments) { const int last_row = enc->mb_h_; // We give a little more than a half work to the main thread. const int split_row = (9 * last_row + 15) >> 4; const int total_mb = last_row * enc->mb_w_; #ifdef WEBP_USE_THREAD const int kMinSplitRow = 2; // minimal rows needed for mt to be worth it const int do_mt = (enc->thread_level_ > 0) && (split_row >= kMinSplitRow); #else const int do_mt = 0; #endif SegmentJob main_job; if (do_mt) { SegmentJob side_job; // Note the use of '&' instead of '&&' because we must call the functions // no matter what. InitSegmentJob(enc, &main_job, 0, split_row); InitSegmentJob(enc, &side_job, split_row, last_row); // we don't need to call Reset() on main_job.worker, since we're calling // WebPWorkerExecute() on it ok &= WebPWorkerReset(&side_job.worker); // launch the two jobs in parallel if (ok) { WebPWorkerLaunch(&side_job.worker); WebPWorkerExecute(&main_job.worker); ok &= WebPWorkerSync(&side_job.worker); ok &= WebPWorkerSync(&main_job.worker); } WebPWorkerEnd(&side_job.worker); if (ok) MergeJobs(&side_job, &main_job); // merge results together } else { // Even for single-thread case, we use the generic Worker tools. InitSegmentJob(enc, &main_job, 0, last_row); WebPWorkerExecute(&main_job.worker); ok &= WebPWorkerSync(&main_job.worker); } WebPWorkerEnd(&main_job.worker); if (ok) { enc->alpha_ = main_job.alpha / total_mb; enc->uv_alpha_ = main_job.uv_alpha / total_mb; AssignSegments(enc, main_job.alphas); } } else { // Use only one default segment.
int VP8EncStartAlpha(VP8Encoder* const enc) { if (enc->has_alpha_) { if (enc->thread_level_ > 0) { WebPWorker* const worker = &enc->alpha_worker_; if (!WebPWorkerReset(worker)) { // Makes sure worker is good to go. return 0; } WebPWorkerLaunch(worker); return 1; } else { return CompressAlphaJob(enc, NULL); // just do the job right away } } return 1; }