compute_quant_matrix  800 libavcodec/agm.c     compute_quant_matrix(s, (2 * s->compression - 100) / 100.0);
compute_quant_matrix  877 libavcodec/agm.c     compute_quant_matrix(s, (2 * s->compression - 100) / 100.0);
compute_quant_matrix  435 libavcodec/speedhq.c     compute_quant_matrix(s->quant_matrix, 100 - quality);