int rtjpeg_decode_frame_yuv420(RTJpegContext *c, AVFrame *f, const uint8_t *buf, int buf_size) { GetBitContext gb; int w = c->w / 16, h = c->h / 16; int x, y; uint8_t *y1 = f->data[0], *y2 = f->data[0] + 8 * f->linesize[0]; uint8_t *u = f->data[1], *v = f->data[2]; init_get_bits(&gb, buf, buf_size * 8); for (y = 0; y < h; y++) { for (x = 0; x < w; x++) { DCTELEM *block = c->block; if (get_block(&gb, block, c->scan, c->lquant) > 0) c->dsp->idct_put(y1, f->linesize[0], block); y1 += 8; if (get_block(&gb, block, c->scan, c->lquant) > 0) c->dsp->idct_put(y1, f->linesize[0], block); y1 += 8; if (get_block(&gb, block, c->scan, c->lquant) > 0) c->dsp->idct_put(y2, f->linesize[0], block); y2 += 8; if (get_block(&gb, block, c->scan, c->lquant) > 0) c->dsp->idct_put(y2, f->linesize[0], block); y2 += 8; if (get_block(&gb, block, c->scan, c->cquant) > 0) c->dsp->idct_put(u, f->linesize[1], block); u += 8; if (get_block(&gb, block, c->scan, c->cquant) > 0) c->dsp->idct_put(v, f->linesize[2], block); v += 8; } y1 += 2 * 8 * (f->linesize[0] - w); y2 += 2 * 8 * (f->linesize[0] - w); u += 8 * (f->linesize[1] - w); v += 8 * (f->linesize[2] - w); } return get_bits_count(&gb) / 8; }