// 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 VP8EncFinishAlpha(VP8Encoder* const enc) {
if (enc->has_alpha_) {
if (enc->thread_level_ > 0) {
WebPWorker* const worker = &enc->alpha_worker_;
if (!WebPWorkerSync(worker)) return 0; // error
}
}
return WebPReportProgress(enc->pic_, enc->percent_ + 20, &enc->percent_);
}
int VP8EncDeleteAlpha(VP8Encoder* const enc) {
int ok = 1;
if (enc->thread_level_ > 0) {
WebPWorker* const worker = &enc->alpha_worker_;
ok = WebPWorkerSync(worker); // finish anything left in flight
WebPWorkerEnd(worker); // still need to end the worker, even if !ok
}
free(enc->alpha_data_);
enc->alpha_data_ = NULL;
enc->alpha_data_size_ = 0;
enc->has_alpha_ = 0;
return ok;
}
int WebPWorkerReset(WebPWorker* const worker) {
int ok = 1;
worker->had_error = 0;
if (worker->status_ < OK) {
#ifdef WEBP_USE_THREAD
if (pthread_mutex_init(&worker->mutex_, NULL) ||
pthread_cond_init(&worker->condition_, NULL)) {
return 0;
}
pthread_mutex_lock(&worker->mutex_);
ok = !pthread_create(&worker->thread_, NULL, WebPWorkerThreadLoop, worker);
if (ok) worker->status_ = OK;
pthread_mutex_unlock(&worker->mutex_);
#else
worker->status_ = OK;
#endif
} else if (worker->status_ > OK) {
ok = WebPWorkerSync(worker);
}
assert(!ok || (worker->status_ == OK));
return ok;
}
