if (size_out > audio_out_size) {
            av_log(NULL, AV_LOG_FATAL, "Internal error, buffer size too small\n");
            exit_program(1);
        }

        // FIXME pass ost->sync_opts as AVFrame.pts in avcodec_encode_audio()
		av_log(0,0,"size_out : %d\n",size_out);
        ret = avcodec_encode_audio(enc, audio_out, size_out,
                                   (short *)buftmp);